At 3.7 million square miles (9.6 million km²) and with 300 million people, the United States is the third or fourth largest country by total area, and third largest by land area and population.[4] The United States is one of the world's most ethnically diverse nations, the product of large-scale immigration from many countries.[5] Its national economy is the world's largest, with a nominal 2006 gross domestic product (GDP) of more than US$13 trillion.[2]

The nation was founded by thirteen colonies of Great Britain located along the Atlantic seaboard. Proclaiming themselves "states," they issued the Declaration of Independence on July 4, 1776. The rebellious states defeated Britain in the American Revolutionary War, the first successful colonial war of independence.[6] A federal convention adopted the current United States Constitution on September 17, 1787; its ratification the following year made the states part of a single republic. The Bill of Rights, comprising ten constitutional amendments, was ratified in 1791. In the nineteenth century, the United States acquired land from France, Spain, Mexico, and Russia, and annexed the Republic of Texas and the Republic of Hawaii. The American Civil War ended slavery in the United States and prevented a permanent split of the country. The Spanish-American War and World War I confirmed its status as a military power. In 1945, the United States emerged from World War II as the first country with nuclear weapons and a permanent member of the United Nations Security Council. The sole remaining superpower in the post–Cold War era, it is the dominant economic, political, cultural, and military force in the world.[7]

Etymology

Common abbreviations of the United States of America include the United States, the U.S., and the U.S.A. Colloquial names for the country include the common America as well as the States. The term Americas, for the lands of the western hemisphere, was coined in the early sixteenth century after Amerigo Vespucci, an Italian explorer and cartographer. The full name of the country was first used officially in the Declaration of Independence, which was the "unanimous Declaration of the thirteen united States of America" adopted by the "Representatives of the united States of America" on July 4, 1776.[8] The current name was finalized on November 15, 1777, when the Second Continental Congress adopted the Articles of Confederation, the first of which states, "The Stile of this Confederacy shall be 'The United States of America.'" Columbia, a once popular name for the Americas and the United States, was derived from Christopher Columbus. It appears in the name District of Columbia. A female personification of Columbia appears on some official documents, including certain prints of U.S. currency.

The standard way to refer to a citizen of the United States is as an American. Though United States is the formal adjective, American and U.S. are the most common adjectives used to refer to the country ("American values," "U.S. forces"). American is rarely used in English to refer to people not connected to the United States.

Geography

The United States is the world's third or fourth largest nation by total area, before or after the People's Republic of China, depending on how two territories disputed by China and India are counted. Including only land area, the United States is third in size behind Russia and China, just ahead of Canada.[9] The continental United States stretches from the Atlantic Ocean to the Pacific Ocean and from Canada to Mexico and the Gulf of Mexico. Alaska is the largest state in area. Separated by Canada, it touches the Pacific and Arctic Oceans. Hawaii occupies an archipelago in the Pacific, southwest of North America. The commonwealth of Puerto Rico, the largest and most populous U.S. territory, is in the northeastern Caribbean. With a few exceptions such as the territory of Guam and the westernmost portions of Alaska, nearly all of the country lies in the western hemisphere.

The coastal plain of the Atlantic seaboard gives way further inland to deciduous forests and the rolling hills of the Piedmont. The Appalachian Mountains divide the eastern seaboard from the Great Lakes and the grasslands of the Midwest. The Mississippi-Missouri River, the world's fourth longest river system, runs mainly north-south through the heart of the country. The flat, fertile prairieland of the Great Plains stretches to the west. The Rocky Mountains, at the western edge of the Great Plains, extend north to south across the continental United States, reaching altitudes higher than 14,000 feet (4,270 m) in Colorado.[10] The area to the west of the Rockies is dominated by deserts such as the Mojave and the rocky Great Basin. The Sierra Nevada range runs parallel to the Rockies, relatively close to the Pacific coast. At 20,320 ft (6,194 m), Alaska's Mount McKinley is the country's tallest peak. Active volcanoes are common throughout the Alexander and Aleutian Islands and the entire state of Hawaii is built upon tropical volcanic islands. The supervolcano underlying Yellowstone National Park in the Rockies is the continent's largest volcanic feature.[11]

Due to the United States' large size and wide range of geographic features, nearly every type of climate is represented. The climate is temperate in most areas, tropical in Hawaii and southern Florida, polar in Alaska, semiarid in the Great Plains west of the 100th meridian, desert in the Southwest, mediterranean in coastal California, and arid in the Great Basin. Extreme weather is not uncommon—the states bordering the Gulf of Mexico are prone to hurricanes and most of the world's tornadoes occur within the continental United States.[12] However, the predominantly temperate climate, infrequent severe drought in the major arable regions, and infrequent severe flooding have helped make the nation a world leader in agriculture.

Environment

With habitats ranging from tropical to Arctic, U.S. plant life is very diverse. The country has more than 17,000 identified native species of flora, including 5,000 in California (home to the tallest, the most massive, and the oldest trees in the world).[13] More than 400 mammal, 700 bird, 500 reptile and amphibian, and 90,000 insect species have been documented.[14] Wetlands such as the Florida Everglades are the base for much of this diversity. The country's ecosystems include thousands of nonnative exotic species that often adversely affect indigenous plant and animal communities. The Endangered Species Act of 1973 protects threatened and endangered species and their habitats, which are monitored by the U.S. Fish and Wildlife Service.

In 1872, the world's first national park was established at Yellowstone. Another fifty-seven national parks and hundreds of other federally managed parks and forests have since been formed.[15] Wilderness areas have been established around the country to ensure long-term protection of pristine habitats. Altogether, the U.S. government regulates 1,020,779 square miles (2,643,807 km²), 28.8 percent of the country's total land area.[16] Protected parks and forestland constitute most of this. As of March 2004, approximately 16 percent of public land under Bureau of Land Management administration was being leased for commercial oil and natural gas drilling;[17] public land is also leased for mining and cattle ranching. The United States is the second largest emitter of carbon dioxide from the burning of fossil fuels after China.[18] The energy policy of the United States is widely debated; many call on the country to take a leading role in fighting global warming.[19]

History

Native Americans and European settlers

The indigenous peoples of the U.S. mainland, including Alaska, migrated from Asia. They began arriving at least 12,000 and as many as 40,000 years ago.[20] Several indigenous communities in the pre-Columbian era developed advanced agriculture, grand architecture, and state-level societies. European explorer Christopher Columbus arrived at Puerto Rico on November 19, 1493, making first contact with the Native Americans. In the years that followed, the majority of the Native American population was killed by epidemics of Eurasian diseases.[21]

Spaniards established the earliest European colonies on the mainland, in the area they named Florida; of these, only St. Augustine, founded in 1565, remains. Later Spanish settlements in the present-day southwestern United States drew thousands through Mexico. French fur traders established outposts of New France around the Great Lakes; France eventually claimed much of the North American interior as far south as the Gulf of Mexico. The first successful British settlements were the Virginia Colony in Jamestown in 1607 and the Pilgrims' Plymouth Colony in 1620. The 1628 chartering of the Massachusetts Bay Colony resulted in a wave of migration; by 1634, New England had been settled by some 10,000 Puritans. Between the late 1610s and the revolution, the British shipped an estimated 50,000 convicts to its American colonies.[22] Beginning in 1614, the Dutch established settlements along the lower Hudson River, including New Amsterdam on Manhattan Island. The small settlement of New Sweden, founded along the Delaware River in 1638, was taken over by the Dutch in 1655.

In the French and Indian War, the colonial extension of the Seven Years War, Britain seized Canada from the French, but the francophone population remained politically isolated from the southern colonies. By 1674, the British had won the former Dutch colonies in the Anglo-Dutch Wars; the province of New Netherland was renamed New York. With the 1729 division of the Carolinas and the 1732 colonization of Georgia, the thirteen British colonies that would become the United States of America were established. All had active local and colonial governments with elections open to most free men, with a growing devotion to the ancient rights of Englishmen and a sense of self government that stimulated support for republicanism. All had legalized the African slave trade. With high birth rates, low death rates, and steady immigration, the colonies doubled in population every twenty-five years. The Christian revivalist movement of the 1730s and 1740s known as the Great Awakening fueled interest in both religion and religious liberty. By 1770, the colonies had an increasingly Anglicized population of three million, approximately half that of Britain itself. Though subject to British taxation, they were given no representation in the Parliament of Great Britain.

Independence and expansion

Tensions between American colonials and the British during the revolutionary period of the 1760s and early 1770s led to the American Revolutionary War, fought from 1775 through 1781. On June 14, 1775, the Continental Congress, convening in Philadelphia, established a Continental Army under the command of George Washington. Proclaiming that "all men are created equal" and endowed with "certain unalienable Rights," the Congress adopted the Declaration of Independence, drafted largely by Thomas Jefferson, on July 4, 1776. In 1777, the Articles of Confederation were adopted, uniting the states under a weak federal government that operated until 1788. Some 70,000–80,000 loyalists to the British Crown fled the rebellious states, many to Nova Scotia and the new British holdings in Canada.[23] Native Americans, with divided allegiances, fought on both sides of the war's western front.

After the British army's defeat by American forces, who were assisted by the French, Great Britain recognized the sovereignty of the thirteen states in 1783. A constitutional convention was organized in 1787 by those who wished to establish a strong national government with power over the states. By June 1788, nine states had ratified the United States Constitution, sufficient to establish the new government; the republic's first Senate, House of Representatives, and president, George Washington, took office in 1789. New York City was the federal capital for a year, before the government relocated to Philadelphia. In 1791, the states ratified the Bill of Rights, ten amendments to the Constitution forbidding federal restriction of personal freedoms and guaranteeing a range of legal protections. Attitudes toward slavery were shifting; a clause in the Constitution protected the African slave trade only until 1808. The Northern states abolished slavery between 1780 and 1804, leaving the slave states of the South as defenders of the "peculiar institution." In 1800, the federal government moved to the newly founded Washington, D.C. The Second Great Awakening made evangelicalism a force behind various social reform movements.

Americans' eagerness to expand westward began a cycle of Indian Wars that stretched to the end of the nineteenth century, as Native Americans were stripped of their land. The Louisiana Purchase of French-claimed territory under President Thomas Jefferson in 1803 virtually doubled the nation's size. The War of 1812, declared against Britain over various grievances and fought to a draw, strengthened American nationalism. A series of U.S. military incursions into Florida led Spain to cede it and other Gulf Coast territory in 1819. The country annexed the Republic of Texas in 1845. The concept of Manifest Destiny was popularized during this time.[24] The 1846 Oregon Treaty with Britain led to U.S. control of the present-day American Northwest. The U.S. victory in the Mexican-American War resulted in the 1848 cession of California and much of the present-day American Southwest. The California Gold Rush of 1848–1849 further spurred western migration. New railways made relocation much less arduous for settlers and increased conflicts with Native Americans. Over a half-century, up to 40 million American bison, commonly called buffalo, were slaughtered for skins and meat and to ease the railways' spread. The loss of the bison, a primary economic resource for the plains Indians, was an existential blow to many native cultures.

Civil War and industrialization

Tensions between slave and free states mounted with increasing disagreements over the relationship between the state and federal governments and violent conflicts over the expansion of slavery into new states. Abraham Lincoln, candidate of the largely antislavery Republican Party, was elected president in 1860. Before he took office, seven slave states declared their secession from the United States, forming the Confederate States of America. The federal government maintained secession was illegal, and with the Confederate attack upon Fort Sumter, the American Civil War began and four more slave states joined the Confederacy. The Union freed Confederate slaves as its army advanced through the South. Following the Union victory in 1865, three amendments to the U.S. Constitution ensured freedom for the nearly four million African Americans who had been slaves,[25] made them citizens, and gave them voting rights. The war and its resolution led to a substantial increase in federal power.[26]

After the war, the assassination of President Lincoln radicalized Republican Reconstruction policies aimed at reintegrating and rebuilding the Southern states while ensuring the rights of the newly freed slaves. The disputed 1876 presidential election resolved by the Compromise of 1877 ended Reconstruction; Jim Crow laws soon disenfranchised many African Americans. In the North, urbanization and an unprecedented influx of immigrants hastened the country's industrialization. The wave of immigration, which lasted until 1929, provided labor for U.S. businesses and transformed American culture. High tariff protections, national infrastructure building, and new banking regulations encouraged industrial growth. The 1867 Alaska purchase from Russia completed the country's mainland expansion. The Wounded Knee massacre in 1890 was the last major armed conflict of the Indian Wars. In 1893, the indigenous monarchy of the Pacific Kingdom of Hawaii was overthrown in a coup led by American residents; the archipelago was annexed by the United States in 1898. Victory in the Spanish-American War that same year demonstrated that the United States was a major world power and resulted in the annexation of Puerto Rico and the Philippines.[27] The Philippines gained independence a half-century later; Puerto Rico remains a commonwealth of the United States.

World War I, Great Depression, and World War II

At the outbreak of World War I in 1914, the United States remained neutral. Americans sympathized with the British and French, although many citizens, mostly Irish and German, opposed intervention.[28] In 1917, the United States joined the Allies, turning the tide against the Central Powers. Reluctant to be involved in European affairs, the Senate did not ratify the Treaty of Versailles, which established the League of Nations. The country pursued a policy of unilateralism, verging on isolationism.[29] In 1920, the women's rights movement won passage of a constitutional amendment granting women's suffrage. In part due to the service of many in the war, Native Americans gained U.S. citizenship in the Indian Citizenship Act of 1924.

During most of the 1920s, the United States enjoyed a period of unbalanced prosperity as farm profits fell while industrial profits grew. A rise in debt and an inflated stock market culminated in the 1929 crash that triggered the Great Depression. After his election as president in 1932, Franklin Delano Roosevelt responded with the New Deal, a range of policies increasing government intervention in the economy. The Dust Bowl of the mid-1930s impoverished many farming communities and spurred a new wave of western migration. The nation would not fully recover from the economic depression until the industrial mobilization spurred by its entrance into World War II. The United States, effectively neutral during the war's early stages after the Nazi invasion of Poland in September 1939, began supplying materiel to the Allies in March 1941 through the Lend-Lease program.

On December 7, 1941, the United States joined the Allies against the Axis Powers after a surprise attack on Pearl Harbor by Japan. World War II cost far more money than any other war in American history,[30] but it boosted the economy by providing capital investment and jobs, while bringing many women into the labor market. Allied conferences at Bretton Woods and Yalta outlined a new system of intergovernmental organizations that placed the United States and Soviet Union at the center of world affairs. As victory was achieved in Europe, a 1945 international conference held in San Francisco produced the United Nations Charter, which became active after the war.[31] The United States, having developed the first nuclear weapons, used them on the Japanese cities of Hiroshima and Nagasaki in August. Japan surrendered on September 2, ending the war.[32]

Superpower

The United States and Soviet Union jockeyed for power after World War II during the Cold War, dominating the military affairs of Europe through the North Atlantic Treaty Organization and the Warsaw Pact. The United States promoted liberal democracy and capitalism, while the Soviet Union promoted communism and a centrally planned economy. The Soviet Union supported dictatorships, as did the United States on occasion, and both engaged in proxy wars. United States troops fought Communist Chinese forces in the Korean War of 1950–53. The House Committee on Un-American Activities pursued a series of investigations into suspected leftist subversion, while Senator Joseph McCarthy became the figurehead of anticommunist sentiment.

The Soviet Union launched the first manned spacecraft in 1961, prompting U.S. efforts to raise proficiency in mathematics and science and President John F. Kennedy's call for the country to be first to land "a man on the moon," achieved in 1969.[33] Kennedy also faced a tense nuclear showdown with Soviet forces in Cuba. Meanwhile, America experienced sustained economic expansion. A growing civil rights movement headed by prominent African Americans, such as Martin Luther King Jr., fought segregation and discrimination, leading to the abolition of Jim Crow laws and passage of the Civil Rights Act of 1964.[34] Following Kennedy's assassination in 1963, his successors expanded a proxy war in Southeast Asia into the unsuccessful Vietnam War.

As a result of the Watergate scandal, in 1974 Richard Nixon became the first U.S. president to resign, rather than be impeached on charges including obstruction of justice and abuse of power. The election of Ronald Reagan as president in 1980 marked a significant rightward shift in American politics. In the late 1980s and 1990s, the Soviet Union's power diminished, leading to its collapse. The leadership role taken by the United States and its allies in the United Nations–sanctioned Gulf War and the Yugoslav wars helped to preserve its position as the world's last remaining superpower. The longest economic expansion in modern U.S. history—from March 1991 to March 2001—encompassed the administration of President Bill Clinton.[35] In 1998, Clinton was impeached by the House on charges relating to a civil lawsuit and a sexual scandal, but was acquitted by the Senate and remained in office.

On September 11, 2001, terrorists struck the World Trade Center in New York City and The Pentagon near Washington, D.C., killing nearly three thousand people. In the aftermath, President George W. Bush launched the War on Terrorism under a military philosophy stressing preemptive war now known as the Bush Doctrine. In late 2001, U.S. forces led a NATO invasion of Afghanistan, removing the Taliban government and al-Qaeda terrorist training camps. Taliban insurgents continue to fight a guerilla war against the NATO-led force. In 2002, the Bush administration began to press for regime change in Iraq on controversial grounds. Lacking the support of NATO, Bush formed a Coalition of the Willing and invaded Iraq in 2003, removing President Saddam Hussein. Although facing both external[36] and internal[37] pressure to withdraw, the United States maintains its military presence in Iraq.

Government and politics

The United States is the world's oldest surviving federation. It is both a representative democracy and a constitutional republic, "in which majority rule is tempered by minority rights protected by law."[38] The government is regulated by a system of checks and balances defined by the United States Constitution, which serves as the country's supreme legal document and as a social contract for the people of the United States. In the American federalist system, citizens are usually subject to three levels of government, federal, state, and local; the local government's duties are commonly split between county and municipal governments. In almost all cases, executive and legislative officials are elected by a plurality vote of citizens by district. There is no proportional representation at the federal level, and it is very rare at lower levels. Federal and state judicial and cabinet officials are typically nominated by the executive branch and approved by the legislature, although some state judges are elected by popular vote. The voting age is eighteen and voter registration is the individual's responsibility.

The federal government is comprised of three branches:

• Legislative: The bicameral Congress, made up of the Senate and the House of Representatives makes federal law, declares war, approves treaties, has the power of the purse, and has the rarely used power of impeachment, by which it can remove sitting members of the government.

• Executive: The president is the commander-in-chief of the military, can veto legislative bills before they become law, and appoints the Cabinet and other officers, who administer and enforce federal laws and policies.

• Judiciary: The Supreme Court and lower federal courts, whose judges are appointed by the president with Senate approval, interpret laws and can overturn laws they deem unconstitutional.

The House of Representatives has 435 members, each representing a congressional district for a two-year term. House seats are apportioned among the fifty states by population every tenth year. As of the 2000 census, seven states have the minimum of one representative, while California, the most populous state, has fifty-three. Each state has two senators, elected at-large to six-year terms; one third of Senate seats are up for election every second year. The president serves a four-year term and may be elected to the office no more than twice. The Supreme Court, led by the Chief Justice of the United States, has nine members, who serve for life.

All laws and procedures of both state and federal governments are subject to review, and any law ruled in violation of the Constitution by the judicial branch is overturned. The original text of the Constitution establishes the structure and responsibilities of the federal government, the relationship between it and the individual states, and essential matters of military and economic authority. Article One protects the right to the "great writ" of habeas corpus, and Article Three guarantees the right to a jury trial in all criminal cases. Amendments to the Constitution require the approval of three-fourths of the states. The Constitution has been amended twenty-seven times, including the 1791 Bill of Rights. The First Amendment guarantees freedom of religion, speech, the press, and peaceable assembly, and the right to petition the government. The other nine amendments of the Bill establish such rights as the right to keep and bear arms; protection from unreasonable search and seizure; the right to due process and just compensation for seized property and protection against double jeopardy and self-incrimination; the right to a speedy trial, impartial jury, and legal counsel; and protection against cruel and unusual punishment. Of the later amendments, the Fourteenth is regarded as particularly important; it obliges each individual state to protect the rights of every citizen to due process and equal protection under the law. The extent to which Americans' constitutional rights are universally upheld in practice is heavily debated.

Politics in the United States have operated under a two-party system for virtually all of the country's history. Since the general election of 1856, the two dominant parties have been the Democratic Party, founded in 1824 (though its roots trace back to 1792), and the Republican Party, founded in 1854. The Senate has two independent members—one is a former Democratic incumbent, the other is a self-described socialist; every member of the House is a Democrat or Republican. An overwhelming majority of state and local officials are also either Democrats or Republicans. Since the Civil War, only one third-party presidential candidate—former president Theodore Roosevelt, running as a Progressive in 1912—has won as much as 20 percent of the popular vote. For elective offices at all levels, state-administered primary elections are held to choose the major party nominees for subsequent general elections.

Within American political culture, the Republican Party is considered "center-right" or conservative and the Democratic Party is considered "center-left" or liberal, but members of both parties have a wide range of views. In the presidential election of 2000, the Democratic candidate, incumbent vice president Al Gore, received a larger share of the popular vote than the Republican candidate, Texas governor George W. Bush. The president is not elected by direct vote, however, but by an indirect electoral college system in which the determining votes are apportioned by state. The disputed vote count in Florida left the election unresolved for over a month until a Supreme Court decision effectively awarded the presidency to Bush. In 2004, Bush won reelection over Democratic challenger Senator John Kerry. Following the 2006 midterm elections, the Democratic Party holds a majority of seats in both the House and Senate for the first time since the election of 1994.[39] In an August 2007 poll, 36 percent of Americans described themselves as "conservative," 34 percent as "moderate," and 25 percent as "liberal."[40] On the other hand, a plurality of adults, 35.9 percent, identify as Democrats, 32.9 percent as independents, and 31.3 percent as Republicans.[41] The states of the Northeast, Great Lakes, and the West Coast are relatively liberal-leaning—they are known in political parlance as "blue states." The "red states" of the South and the Rocky Mountains lean conservative. The academic realm diverges widely from the general political balance: 72 percent of college faculty members identify as liberal and only 15 percent as conservative.[42] The military is considerably more conservativethan the general public, with 46 percent of active personnel identifying as Republican in December 2006, down from 60 percent in 2004.[43]

Foreign relations and military

The United States has vast economic, political, and military influence on a global scale, which makes its foreign policy a subject of great interest around the world. Almost all countries have embassies in Washington, D.C., and many host consulates around the country. Likewise, nearly all nations host American diplomatic missions. However, Cuba, Iran, North Korea, Bhutan, and Sudan do not have formal diplomatic relations with the United States.[44]

American isolationists have often been at odds with internationalists, as anti-imperialists have been with promoters of Manifest Destiny and American Empire. American imperialism in the Philippines drew sharp rebukes from Mark Twain, philosopher William James, and many others. Later, President Woodrow Wilson played a key role in creating the League of Nations, but the Senate prohibited American membership in it. Isolationism became a thing of the past when the United States took a lead role in founding the United Nations, becoming a permanent member of the Security Council and host to the United Nations headquarters. The United States enjoys a special relationship with Britain and strong ties with Australia, New Zealand, Japan, Israel, and fellow NATO members. It also works closely with its neighbors through the Organization of American States and free trade agreements such as the trilateral North American Free Trade Agreement with Canada and Mexico. In 2005, the United States spent $27.3 billion on official development assistance, the most in the world; however, as a share of gross national income (GNI), the U.S. contribution of 0.22 percent ranked twentieth of twenty-two donor states. On the other hand, nongovernmental sources such as private foundations, corporations, and educational and religious institutions donated $95.5 billion. The total of $122.8 billion is again the most in the world and seventh in terms of GNI percentage.[45]

The president holds the title of commander-in-chief of the nation's armed forces and appoints its leaders, the secretary of defense and the Joint Chiefs of Staff. The United States Department of Defense administers the armed forces, including the Army, the Navy, the Marine Corps, and the Air Force. The Coast Guard falls under the jurisdiction of the Department of Homeland Security in peacetime and the Department of the Navy in times of war. In 2005, the military had 1.38 million personnel on active duty,[46] along with several hundred thousand each in the Reserves and the National Guard for a total of 2.3 million troops. The Department of Defense also employs approximately 700,000 civilians, disregarding contractors. Military service is voluntary, though conscription may occur in wartime through the Selective Service System. The rapid deployment of American forces is facilitated by the Air Force's large fleet of transportation aircraft and aerial refueling tankers, the Navy's fleet of eleven active aircraft carriers, and Marine Expeditionary Units at sea in the Navy's Atlantic and Pacific fleets. Outside of the American homeland, the U.S. military is deployed to 770 bases and facilities, on every continent except Antarctica.[47] Due to the extent of its global military presence, scholars describe the United States as maintaining an "empire of bases."[48]

U.S. military spending in 2006, over $528 billion, was 46 percent of the entire military spending in the world and greater than the next fourteen largest national military expenditures combined. (In purchasing power parity terms, it was larger than the next six such expenditures combined.) The per capita spending of $1,756 was approximately ten times the world average.[49] At 4.06 percent of GDP, U.S. military spending ranked 27th out of 172 nations.[50] The official Department of Defense budget in 2006, $419.3 billion, was a 5 percent increase over 2005.[51] The total cost to the United States of the war in Iraq is estimated to come to $2.267 trillion.[52] As of August 8, 2007, the United States had suffered 3,680 military fatalities during the war and over 26,500 wounded.[53]

Economy

The United States has a capitalist mixed economy, which is fueled by abundant natural resources, a well-developed infrastructure, and high productivity. According to the International Monetary Fund, the United States GDP of more than $13 trillion constitutes 20 percent of the gross world product. Only the collective GDP of the European Union is greater. The country ranks eighth in the world in nominal GDP per capita and fourth in GDP per capita at purchasing power parity.[2] The United States is the largest importer of goods and second largest exporter. Canada, China, Mexico, Japan, and Germany are its top trading partners.[64] The leading export commodity is electrical machinery, while vehicles constitute the leading import.[65]

The private sector constitutes the bulk of the economy, with government activity accounting for 12.4 percent of the GDP.[66] The economy is postindustrial, with the service sector contributing over 75 percent of GDP. The leading business field by gross business receipts is wholesale and retail trade; by net income it is finance and insurance.[67] The United States remains an industrial power, with chemical products the leading manufacturing field.[68] It is the world's number one producer of electrical and nuclear energy, as well as liquid natural gas, aluminum, sulfur, phosphates, and salt. Agriculture accounts for only 1 percent of GDP but 60 percent of the world's agricultural production.[69] The country's leading cash crop is marijuana.[70]

Three quarters of U.S. business firms have no payroll, but they account for only a small fraction of business receipts. Firms with payrolls of 500 or more employ 49.1 percent of all paid workers; in 2002, they accounted for 59.1 percent of business receipts.[71] The United States ranks third in the World Bank's Ease of Doing Business Index.[72] Compared to Europe, U.S. property and corporate income taxes are generally higher, while labor and, particularly, consumption taxes are lower.[73] The U.S. national debt is the world's largest; in 2005, it was 23 percent of the global total.[74] As a percentage of GDP, U.S. debt ranked thirtieth out of 120 countries for which data is available.[75] Foreign entities hold 27.5 percent of the U.S. debt, up from 13 percent in 1988.[74]

In 2005, 155 million persons were employed with earnings, of whom 80 percent worked in full-time jobs.[76] The majority, 79 percent, were employed in the service sector.[77] With approximately 15.5 million people, health care and social assistance is the leading field of employment.[78] About 12 percent of American workers were unionized, compared to 30 percent in Western Europe.[79] The U.S. ranks number one in the ease of hiring and firing workers, according to the World Bank.[72] Americans tend to work considerably more hours annually than workers in other developed nations, taking fewer and shorter vacations. Between 1973 and 2003, a year's work for the average American grew by 199 hours.[80] Partly as a result, the United States maintains the highest labor productivity in the world. However, it no longer leads the world in productivity per hour as it did from the 1950s through the early 1990s; workers in Norway, France, Belgium, and Luxembourg are now more productive per hour.[81] Spending on the social safety net is relatively low: the United States redistributes about 9 percent of GDP through social protection programs, compared to 19 percent in the European Union.[82]

Income and social class

According to the U.S. Census Bureau, the pretax median household income in 2005 was $46,326;[54] the two-year average ranged from $60,246 in New Jersey to $34,396 in Mississippi.[83] Using purchasing power parity exchange rates, these income levels are similar to those found in other postindustrial nations such as Norway ($61,294 [mean])[84] and the United Kingdom ($39,915).[85] Approximately 13 percent of Americans were below the federally designated poverty line.[54][62] The number of poor Americans, nearly 37 million, was actually 4 million more than in 2001, the bottom year of the most recent U.S. recession.[86] Between 1967 and 2005, median household income rose 30.6 percent in constant dollars, largely due to the growing number of dual-earner households. In 2005, median income for nonelderly households declined for the fifth consecutive year.[86] Though the standard of living has improved for nearly all classes since the late 1970s,[87] income inequality has grown substantially.[88][89] The share of income received by the top 1 percent has risen considerably while the share of income of the bottom 90 percent has fallen, with the gap between the two groups being roughly as large in 2005 as in 1928.[90] According to the standard Gini index, income inequality in the United States is higher than in any European nation.[91] Some economists, such as Alan Greenspan, see rising income inequality as a cause for concern.[92]

While American social classes lack defined boundaries,[89] sociologists point to social class as a crucial societal variable. Occupation, educational attainment, and income are used as the main indicators of socioeconomic status.[93] Dennis Gilbert of Hamilton College has proposed a system, adapted by other sociologists,[94] with six social classes: an upper, or capitalist, class consisting of the wealthy and powerful (1%), an upper middle class consisting of highly educated professionals (15%), a middle class consisting of semiprofessionals and craftsmen (33%), a working class consisting of clerical and blue-collar workers who conduct highly routinized tasks (33%), and two lower classes—the working poor (13%) and a largely unemployed underclass (12%).[89] Where it was once common for middle-class households to employ domestic servants, many domestic tasks are now outsourced to the service industry.[95] Wealth is highly concentrated: The richest 10 percent of the adult population possesses 69.8 percent of the country's household wealth, the second-highest share of any democratic developed nation.[96] The top 1 percent possesses 33.4 percent of net wealth, including more than half of the total value in publicly traded stocks.[97] Though the American Dream, or the perception that Americans enjoy high social mobility, played a key role in attracting immigrants to the United States, particularly in the late 1800s,[98] some analysts find that the United States has relatively low social mobility compared to Western Europe and Canada.[99]

Science, technology, and transportation

The United States has been a leader in scientific research and technological innovation since the late nineteenth century, attracting immigrants such as Albert Einstein. The bulk of research and development funding, 64 percent, comes from the private sector.[100] The United States leads the world in scientific research papers and impact factor.[101] In 1876, Alexander Graham Bell was awarded the first patent for the telephone. The laboratory of Thomas Edison developed the phonograph, the first long-lasting light bulb, and the first viable movie camera. In the early twentieth century, the automobile companies of Ransom Olds and Henry Ford pioneered assembly line manufacturing. The Wright brothers, in 1903, made what is recognized as the "first sustained and controlled heavier-than-air powered flight."[102] During World War II, the United States developed nuclear weapons, ushering in the atomic age. The space race produced rapid advances in rocketry, material science, computers, and many other areas. The United States largely developed the Arpanet and its successor, the Internet. Americans enjoy high levels of access to technological consumer goods.[103] Almost half of U.S. households have broadband Internet service.[104] The country is the primary developer and grower of genetically modified food; more than half of the world's land planted with biotech crops is in the United States.[105]

As of 2003, there were 759 automobiles per 1,000 Americans, compared to 472 per 1,000 inhabitants of the European Union the following year.[106] Approximately 39 percent of personal vehicles are vans, SUVs, or light trucks.[107] The average American adult (accounting for all drivers and nondrivers) spends 55 minutes behind the wheel every day, driving 29 miles.[108] The civil airline industry is entirely privatized, while most major airports are publicly owned. The five largest airlines in the world by passengers carried are all American; American Airlines is number one.[109] Of the world's thirty busiest passenger airports, sixteen are in the United States, including the busiest, Hartsfield-Jackson Atlanta International Airport (ATL).[110] The U.S. intercity passenger rail system is relatively weak.[111] Only 9 percent of total U.S. work trips employ mass transit, compared to 38.8 percent in Europe.[112] Bicycle usage is minimal, well below European levels.[113]

Demographics

On October 17, 2006, the United States population was estimated by the U.S. Census Bureau to be 300,000,000.[114] The U.S. population included an estimated 12 million unauthorized migrants,[115] of whom an estimated 1 million were uncounted by the Census Bureau.[116] The overall growth rate is 0.89 percent,[77] compared to 0.16 percent in the European Union.[117] The birth rate of 14.16 per 1,000 is 30 percent below the world average, while higher than any European country except for Albania and Ireland.[118] In 2006, 1.27 million immigrants were granted legal residence. Mexico has been the leading source of new U.S. residents for over two decades; since 1998, China, India, and the Philippines have been in the top four sending countries every year.[119] The United States is the only industrialized nation in which large population increases are projected.[120] The United States has a very diverse population—thirty-one ancestry groups have more than a million members.[121] Whites are the largest racial group, with German Americans, Irish Americans, and English Americans constituting three of the country's four largest ancestry groups.[121] African Americans, mostly descendants of former slaves, constitute the nation's largest racial minority and third largest ancestry group.[62][121] Asian Americans are the country's second largest racial minority; the two largest Asian American ancestry groups are Chinese and Filipino.[121] In 2005, the U.S. population included an estimated 4.5 million people with some Native American or Alaskan native ancestry (2.4 million exclusively of such ancestry) and nearly 1 million with some native Hawaiian or Pacific island ancestry (0.4 million exclusively).[122][62]

Hispanic American population growth is a major demographic trend. Counted collectively, the approximately 42 million Hispanic Americans constitute the largest ethnic minority in the country.[122] About 63 percent of the Hispanic American community is of Mexican origin.[123] Between 2000 and 2004, the country's Hispanic population increased 14 percent while the non-Hispanic population rose just 2 percent.[123] Much of this growth is due to immigration: As of 2004, 12 percent of the U.S. population was foreign-born, over half that number from Latin America.[124] Fertility is also a factor: The average Hispanic woman gives birth to three children in her lifetime. The comparable fertility rate is 2.2 for African American women and 1.8 for non-Hispanic whites (below the replacement rate of 2.1).[120] Hispanics accounted for nearly half of the national population growth of 2.9 million between July 2005 and July 2006.[125] It is estimated on the basis of current trends that by 2050 non-Hispanic whites will be just 50.1 percent of the U.S. population, compared to 69.4 percent in 2000.[126] They are already less than half the population in four "majority-minority states": California,[127] New Mexico,[128] Hawaii,[129] and Texas.[130]

About 83 percent of the population lives in one of the country's 361 metropolitan areas.[131] In 2005, 254 incorporated places in the United States had populations over 100,000, nine cities had more than 1 million residents, and four global cities had over 2 million (New York City, Los Angeles, Chicago, and Houston).[132] The United States has fifty metropolitan areas with populations greater than 1 million.[133] Of the fifty fastest-growing metro areas, twenty-three are in the West and twenty-five in the South. Among the country's twenty most populous metro areas, those of Dallas (the fourth largest), Houston (sixth), and Atlanta (ninth) saw the largest numerical gains between 2000 and 2006, while that of Phoenix (thirteenth) grew the largest in percentage terms.[131] In thirty-five of the country's fifty largest cities, non-Hispanic whites are or soon will be in the minority.[134]

Language and religion

In 2003, about 215 million, or 82 percent of the population aged five years and older, spoke only English at home. Spanish, spoken by over 10 percent of the population at home, is the second most common language and the most widely taught foreign language.[136][137] Immigrants seeking naturalization must know English. Some Americans advocate making English the country's official language, as it is in at least twenty-eight states.[138] Both Hawaiian and English are official languages in Hawaii by state law.[139] Several insular territories also grant official recognition to their native languages, along with English: Samoan and Chamorro are recognized by Samoa and Guam, respectively; Carolinian and Chamorro are recognized by the Northern Mariana Islands; Spanish is an official language of Puerto Rico. While neither has an official language, New Mexico has laws providing for the use of both English and Spanish, as Louisiana does for English and French.[140]

The United States government does not audit Americans' religious beliefs.[141] In a private survey conducted in 2001, 76.7 percent of American adults identified themselves as Christian, down from 86.4 percent in 1990. Various Protestant denominations accounted for 52 percent, while Roman Catholics, at 24.5 percent, were the largest individual denomination.[142] A different study describes white evangelicals, 26.3 percent of the population, as the country's largest religious cohort;[143] evangelicals of all races are estimated at 30–35 percent.[144] The total reporting non-Christian religions in 2001 was 3.7 percent, up from 3.3 percent in 1990. The leading non-Christian faiths were Judaism (1.4 percent), Islam (0.5 percent), Buddhism (0.5 percent), Hinduism (0.4 percent), and Unitarian Universalism (0.3 percent). Between 1990 and 2001, the number of Muslims and Buddhists more than doubled. From 8.2 percent in 1990, 14.2 percent in 2001 described themselves as agnostic, atheist, or simply having no religion,[142] still significantly less than in other postindustrial countries such as Britain (44 percent) and Sweden (69 percent).[145]

Education and health

American public education is operated by state and local governments, regulated by the United States Department of Education through restrictions on federal grants. Children are obliged in most states to attend school from the age of six or seven (generally, kindergarten or first grade) until they turn eighteen (generally bringing them through 12th grade, the end of high school); some states allow students to leave school at sixteen or seventeen.[146] About 12 percent of children are enrolled in parochial or nonsectarian private schools. Just over 2 percent of children are homeschooled.[147] The United States has many competitive private and public institutions of higher education; 168 U.S. universities are in the world's top 500, 17 in the top 20.[148] There are also many smaller universities and liberal arts colleges, and local community colleges of varying quality with open admission policies. The United States has a basic literacy rate of approximately 99 percent.[77][149] Of Americans twenty-five and older, 84.6 percent graduated from high school, 52.6 percent attended some college, 27.2 percent earned a bachelor's degree, and 9.6 percent earned graduate degrees.[150] The United Nations assigns the United States an Education Index of 99.9, tieing it with twenty other nations for the top score.[151]

The American life expectancy of 77.8 years at birth[152] is a year shorter than the overall figure in Western Europe, and three to four years lower than that of Norway and Switzerland.[153] Over the past two decades, the country's rank in life expectancy has dropped from 11th to 42nd place in the world.[154] The infant mortality rate of 6.37 per thousand likewise places the United States 42nd out of 221 countries, behind all of Western Europe.[155] Approximately one-third of the adult population is obese and an additional third is overweight;[156] the obesity rate, the highest in the industrialized world, has more than doubled in the last quarter-century.[157] Obesity-related type 2 diabetes is considered epidemic by healthcare professionals.[158] The U.S. adolescent pregnancy rate, 79.8 per 1,000 women, is nearly four times that of France and five times that of Germany.[159] Abortion, legal on demand, is a source of great political controversy. Many states ban public funding of the procedure and have laws to restrict late-term abortions, require parental notification for minors, and mandate a waiting period prior to treatment. Geographical access to abortion is limited: 87 percent of U.S. counties have no abortion provider.[160] Nonetheless, while the incidence of abortion is in decline, the U.S. abortion ratio of 241 per 1,000 live births and abortion rate of 15 per 1,000 women aged 15–44 remain higher than those of most Western nations.[161]

The United States healthcare system far outspends any other nation's, measured in both per capita spending and percentage of GDP.[162] Unlike most developed countries, the U.S. healthcare system is not fully socialized, instead relying on a mix of public and private funding. In 2004, private insurance paid for 36 percent of personal health expenditure, private out-of-pocket payments covered 15 percent, and federal, state, and local governments paid for 44 percent.[163] Medical bills are the most common reason for personal bankruptcy in the United States.[164] In 2005, 46.6 million Americans, or 15.9 percent of the population, were uninsured, 5.4 million more than in 2001. The primary cause of the decline in coverage is the drop in the number of Americans with employer-sponsored health insurance, which fell from 62.6 percent in 2001 to 59.5 percent in 2005.[86] Approximately one third of the uninsured lived in households with annual incomes greater than $50,000, with half of those having an income over $75,000.[54] Another third were eligible but not registered for public health insurance.[165] In 2006, Massachusetts became the first state to mandate health insurance;[166] California is considering similar legislation.[167]

Crime and punishment

Law enforcement in the United States is primarily the responsibility of local police and sheriff's departments, with state police providing broader services. Federal agencies such as the Federal Bureau of Investigation (FBI) and the U.S. Marshals Service have specialized duties. At the federal level and in almost every state, jurisprudence operates on a common law system. State courts conduct most criminal trials; federal courts handle certain designated crimes as well as appeals from state systems.

Relative to other developed countries, the United States has moderately high levels of violent crime and particularly high levels of gun violence and homicide.[168] In 2005, there were 5.6 murders per 100,000 per