United States.html



United States of America
Flag Great Seal
Motto: In God We Trust  (official) E Pluribus Unum   (Out of Many, One; Latin, traditional)
Anthem: "The Star-Spangled Banner"
Capital		Washington, D.C. 38°53′N 77°01′W / 38.883, -77.017
Largest city		New York City
Official languages		None at federal level1
National language		English (de facto)2
Demonym		American
Government		Federal constitutional republic
-	President	George W. Bush (R)
-	Vice President	Dick Cheney (R)
-	Speaker of the House	Nancy Pelosi (D)
-	Chief Justice	John Roberts
Independence from the Kingdom of Great Britain
-	Declared	July 4, 1776
-	Recognized	September 3, 1783
-	Current constitution	June 21, 1788
Area
-	Total	9,826,630 km² 1(3rd/4th3) 3,794,066 sq mi
-	Water (%)	6.76
Population
-	2008 estimate	305,722,0002 (3rd4)
-	2000 census	281,421,9063
-	Density	31/km² (180th) 80/sq mi
GDP (PPP)		2008 estimate
-	Total	$14.334 trillion4 (1st)
-	Per capita	$47,0254 (6th)
GDP (nominal)		2008 estimate
-	Total	$14.334 trillion4 (1st)
-	Per capita	$47,0254 (17th)
Gini (2007)		46.35
HDI (2005)		0.951 (high6) (12th)
Currency		United States dollar ($) (USD)
Time zone		(UTC-5 to -10)
-	Summer (DST)	(UTC-4 to -10)
Internet TLD		.us .gov .mil .edu
Calling code		+1
1	English is the official language of at least 28 states—some sources give a higher figure, based on differing definitions of "official." English and Hawaiian are both official languages in the state of Hawaii.
2	English is the de facto language of American government and the sole language spoken at home by 82% of Americans age five and older. Spanish is the second most commonly spoken language.
3	Whether the United States or the People's Republic of China is larger is disputed. The figure given is per the U.S. Central Intelligence Agency's World Factbook. Other sources give smaller figures. All authoritative calculations of the country's size include only the fifty states and the District of Columbia, not the territories.
4	The population estimate includes people whose usual residence is in the fifty states and the District of Columbia, including noncitizens. It does not include either those living in the territories, amounting to more than four million U.S. citizens (most in Puerto Rico), or U.S. citizens living outside the United States.

The United States of America (commonly referred to as the United States, the U.S., the USA, the States or America) is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwest of the continent, with Canada to its east and Russia to the west across the Bering Strait. The state of Hawaii is an archipelago in the mid-Pacific. The country also possesses several territories, or insular areas, scattered around the Caribbean and Pacific.

At 3.79 million square miles (9.83 million km²) and with about 305 million people, the United States is the third or fourth largest country by total area, and third largest by land area and by population. The United States is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries.⁷ The U.S. economy is the largest national economy in the world, with an estimated 2008 gross domestic product (GDP) of US$14.3 trillion (23% of the world total based on nominal GDP and almost 21% at purchasing power parity).⁴⁸

The nation was founded by thirteen colonies of Great Britain located along the Atlantic seaboard. On July 4, 1776, they issued the Declaration of Independence, which proclaimed their independence from Great Britain and their formation of a cooperative union. The rebellious states defeated Great Britain in the American Revolutionary War, the first successful colonial war of independence.⁹ 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 with a strong central government. The Bill of Rights, comprising ten constitutional amendments guaranteeing many fundamental civil rights and freedoms, was ratified in 1791.

In the 19th century, the United States acquired land from France, Spain, the United Kingdom, Mexico, and Russia, and annexed the Republic of Texas and the Republic of Hawaii. Disputes between the agrarian South and industrial North over states' rights and the expansion of the institution of slavery provoked the American Civil War of the 1860s. The North's victory prevented a permanent split of the country and led to the end of legal slavery in the United States. By the 1870s, the national economy was the world's largest.¹⁰ The Spanish–American War and World War I confirmed the country's status as a military power. In 1945, the United States emerged from World War II as the first country with nuclear weapons, a permanent member of the United Nations Security Council, and a founding member of NATO. The end of the Cold War left the United States as the sole superpower. The country accounts for approximately 50% of global military spending and is a leading economic, political, and cultural force in the world.¹¹

Etymology

The term America, for the lands of the western hemisphere, is believed to have been coined in 1507 after Amerigo Vespucci, an Italian explorer and cartographer.¹² 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, 1776.¹³ 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.'" The short form United States is also standard. Other common forms include the U.S., the USA, and America. Colloquial names include the U.S. of A. and the States. Columbia, a once popular name for the United States, was derived from Christopher Columbus. It appears in the name "District of Columbia".

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.¹⁴

The phrase "the United States" was originally treated as plural—e.g., "the United States are"—including in the Thirteenth Amendment to the United States Constitution, ratified in 1865. It became common to treat it as singular—e.g., "the United States is"—after the end of the Civil War. The singular form is now standard; the plural form is retained in the idiom "these United States."¹⁵

Geography and environment

Main articles: Geography of the United States, Climate of the United States, and Environment of the United States

Topographic map of the contiguous United States

The United States is situated almost entirely in the western hemisphere: the contiguous U.S. stretches from the Pacific Ocean on the west to the Atlantic Ocean on the east, with the Gulf of Mexico to the southeast; it is bordered by Canada on the north and Mexico on the south. Alaska is the largest state in area; separated from the contiguous U.S. by Canada, it touches the Pacific on the south and the Arctic Ocean on the north. Hawaii occupies an archipelago in the central Pacific, southwest of North America. After Russia and Canada, the U.S. is the world's third or fourth largest nation by total area, ranking just above or below China. The ranking varies depending on how two territories disputed by China and India are counted and how the total size of the U.S. is calculated: the CIA World Factbook gives 3,794,083 sq mi (9,826,630 km²),¹ the United Nations Statistics Division gives 3,717,813 sq mi (9,629,091 km²),¹⁶ and the Encyclopedia Britannica gives 3,676,486 sq mi (9,522,055 km²).¹⁷ Including only land area, the U.S. is third in size behind Russia and China, just ahead of Canada.¹⁸ The U.S. also possesses several insular territories scattered around the West Indies (e.g., the commonwealth of Puerto Rico) and the Pacific (e.g., Guam).

View of the Rocky Mountains in Colorado

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 prairie of the Great Plains stretches to the west, interrupted by a highland region in the southeast. The Rocky Mountains, at the western edge of the Great Plains, extend north to south across the country, reaching altitudes higher than 14,000 feet (4,300 m) in Colorado. Farther west are the rocky Great Basin and deserts such as the Mojave. The Sierra Nevada and Cascade mountain ranges run close to the Pacific coast. At 20,320 feet (6,194 m), Alaska's Mount McKinley is the country's tallest peak. Active volcanoes are common throughout Alaska's Alexander and Aleutian Islands, and Hawaii consists of volcanic islands. The supervolcano underlying Yellowstone National Park in the Rockies is the continent's largest volcanic feature.¹⁹

The bald eagle has been the national bird of the United States since 1782

The U.S., with its large size and geographic variety, includes most climate types. To the east of the 100th meridian, the climate ranges from humid continental in the north to humid subtropical in the south. The southern tip of Florida is tropical, as is Hawaii. The Great Plains west of the 100th meridian are semi-arid. Much of the Western mountains are alpine. The climate is arid in the Great Basin, desert in the Southwest, Mediterranean in coastal California, and oceanic in coastal Oregon and Washington and southern Alaska. Most of Alaska is subarctic or polar. 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 country, mainly in the Midwest's Tornado Alley.²⁰

The U.S. ecology is very diverse: about 17,000 species of vascular plants occur in the contiguous U.S. and Alaska, and over 1,800 species of flowering plants are found in Hawaii, few of which occur on the mainland.²¹ The U.S. is home to more than 400 mammal, 700 bird, 500 reptile and amphibian, and 90,000 insect species.²² The Endangered Species Act of 1973 protects threatened and endangered species and their habitats, which are monitored by the United States Fish and Wildlife Service. There are fifty-eight national parks and hundreds of other federally managed parks, forests, and wilderness areas.²³ Altogether, the government regulates 28.8% of the country's land area.²⁴ Most of this is protected, though some is leased for oil and gas drilling,²⁵ mining, or cattle ranching.

History

Main article: History of the United States

Native Americans and European settlers

Main articles: Native Americans in the United States, European colonization of the Americas, and Thirteen Colonies

The indigenous peoples of the U.S. mainland, including Alaska Natives, migrated from Asia. They began arriving at least 12,000 and as many as 40,000 years ago.²⁶ Some, such as the pre-Columbian Mississippian culture, developed advanced agriculture, grand architecture, and state-level societies. After Europeans began settling the Americas, many millions of indigenous Americans died from epidemics of imported diseases such as smallpox.²⁷

The Mayflower transported Pilgrims to the New World in 1620, as depicted in William Halsall's The Mayflower in Plymouth Harbor, 1882

In 1492, Genoese explorer Christopher Columbus, under contract to the Spanish crown, reached several Caribbean islands, making first contact with the indigenous people. On April 2, 1513, Spanish conquistador Juan Ponce de León landed on what he called "La Florida"—the first documented European arrival on what would become the U.S. mainland. Of Spain's settlements in the region, 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, down to the Gulf of Mexico. The first successful English 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 American Revolution, about 50,000 convicts were shipped to Britain's American colonies.²⁸ Beginning in 1614, the Dutch settled along the lower Hudson River, including New Amsterdam on Manhattan Island.

In 1674, the Dutch ceded their American territory to England; the province of New Netherland was renamed New York. Many new immigrants, especially to the South, were indentured servants—some two-thirds of all Virginia immigrants between 1630 and 1680.²⁹ By the turn of the century, African slaves were becoming the primary source of bonded labor. 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 local governments with elections open to most free men, with a growing devotion to the ancient rights of Englishmen and a sense of self-government stimulating support for republicanism. All legalized the African slave trade. With high birth rates, low death rates, and steady immigration, the colonial population grew rapidly. The Christian revivalist movement of the 1730s and 1740s known as the Great Awakening fueled interest in both religion and religious liberty. In the French and Indian War, British forces seized Canada from the French, but the francophone population remained politically isolated from the southern colonies. Excluding the Native Americans (popularly known as "American Indians"), who were being displaced, those thirteen colonies had a population of 2.6 million in 1770, about one-third that of Britain; nearly one in five Americans were black slaves.³⁰ Though subject to British taxation, the American colonials had no representation in the Parliament of Great Britain.

Independence and expansion

Main articles: American Revolution, American Revolutionary War, and Manifest Destiny

Declaration of Independence, by John Trumbull, 1817–18

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. That date is now celebrated annually as America's Independence Day. In 1777, the Articles of Confederation established a weak federal government that operated until 1789.

After the British defeat by American forces who were assisted by the French, Great Britain recognized the independence of the United States and the states' sovereignty over American territory west to the Mississippi River. A constitutional convention was organized in 1787 by those wishing to establish a strong national government, with powers of taxation. The United States Constitution was ratified in 1788, and the new republic's first Senate, House of Representatives, and president—George Washington—took office in 1789. The Bill of Rights, forbidding federal restriction of personal freedoms and guaranteeing a range of legal protections, was adopted in 1791.

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." The Second Great Awakening, beginning about 1800, made evangelicalism a force behind various social reform movements, including abolitionism.

Territorial acquisitions by date

Americans' eagerness to expand westward prompted a long series of Indian Wars and an Indian removal policy that stripped the native peoples of their land. The Louisiana Purchase of French-claimed territory under President Thomas Jefferson in 1803 almost doubled the nation's size. The War of 1812, declared against Britain over various grievances and fought to a draw, strengthened U.S. nationalism. A series of U.S. military incursions into Florida led Spain to cede it and other Gulf Coast territory in 1819. The U.S. annexed the Republic of Texas in 1845. The concept of Manifest Destiny was popularized during this time.³¹ 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 1848–49 further spurred western migration. New railways made relocation easier for settlers and increased conflicts with Native Americans. Over a half-century, up to 40 million American bison, or buffalo, were slaughtered for skins and meat and to ease the railways' spread. The loss of the buffalo, a primary resource for the plains Indians, was an existential blow to many native cultures.

Civil War and industrialization

Main articles: American Civil War, Reconstruction era of the United States, and Spanish-American War

Battle of Gettysburg, lithograph by Currier & Ives, ca. 1863

Tensions between slave and free states mounted with arguments over the relationship between the state and federal governments, as well as violent conflicts over the spread 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—which the federal government maintained was illegal—and formed the Confederate States of America. With the Confederate attack upon Fort Sumter, the American Civil War began and four more slave states joined the Confederacy. Lincoln's Emancipation Proclamation committed the Union to ending slavery. 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,³² made them citizens, and gave them voting rights. The war and its resolution led to a substantial increase in federal power.³³

Immigrants landing at Ellis Island, New York, 1902

After the war, the assassination of Lincoln radicalized Republican Reconstruction policies aimed at reintegrating and rebuilding the Southern states while ensuring the rights of the newly freed slaves. The resolution of the disputed 1876 presidential election 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 from Southern and Eastern Europe hastened the country's industrialization. The wave of immigration, lasting until 1929, provided labor and transformed American culture. High tariff protections, national infrastructure building, and new banking regulations encouraged 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 U.S. annexed the archipelago in 1898. Victory in the Spanish-American War the same year demonstrated that the U.S. was a world power and led to the annexation of Puerto Rico, Guam, and the Philippines. The Philippines gained independence a half-century later; Puerto Rico and Guam remain U.S. territories.

World War I, Great Depression, and World War II

Main articles: American Expeditionary Force, Great Depression in the United States, and Military history of the United States during World War II

An abandoned farm in South Dakota during the Dust Bowl, 1936

At the outbreak of World War I in 1914, the United States remained neutral. Most Americans sympathized with the British and French, although many opposed intervention.³⁴ In 1917, the U.S. joined the Allies, turning the tide against the Central Powers. After the war, 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.³⁵ In 1920, the women's rights movement won passage of a constitutional amendment granting women's suffrage. The prosperity of the Roaring Twenties ended with the Wall Street Crash of 1929 that triggered the Great Depression. After his election as president in 1932, Franklin D. 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 U.S., effectively neutral during World War II's early stages after Nazi Germany's 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 U.S. 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,³⁶ but it boosted the economy by providing capital investment and jobs. Among the major combatants, the U.S. was the only nation to become richer—indeed, far richer—instead of poorer because of the war.³⁷ Allied conferences at Bretton Woods and Yalta outlined a new system of international organizations that placed the U.S. and Soviet Union at the center of world affairs. As victory was won in Europe, a 1945 international conference held in San Francisco produced the United Nations Charter, which became active after the war.³⁸ The U.S., 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.³⁹

Cold War and civil rights

Main articles: Cold War, African-American Civil Rights Movement (1955–1968), and Vietnam War

Martin Luther King, Jr. delivering his "I Have a Dream" speech, 1963

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

The 1961 Soviet launch of the first manned spaceflight prompted President John F. Kennedy's call for the U.S. to be first to land "a man on the moon," achieved in 1969. Kennedy also faced a tense nuclear showdown with Soviet forces in Cuba. Meanwhile, the U.S. experienced sustained economic expansion. A growing civil rights movement, led by African Americans such as Rosa Parks and Martin Luther King, Jr., fought segregation and discrimination. Following Kennedy's assassination in 1963, the Civil Rights Act of 1964 and Voting Rights Act of 1965 were passed under President Lyndon B. Johnson. Johnson and his successor, Richard Nixon, expanded a proxy war in Southeast Asia into the unsuccessful Vietnam War. A widespread countercultural movement grew, fueled by opposition to the war, black nationalism, and the sexual revolution. Betty Friedan, Gloria Steinem, and others led a new wave of feminism that sought political, social, and economic equality for women.

As a result of the Watergate scandal, in 1974 Nixon became the first U.S. president to resign, rather than be impeached on charges including obstruction of justice and abuse of power; he was succeeded by Vice President Gerald Ford. The Jimmy Carter administration of the late 1970s was marked by stagflation and the Iran hostage crisis. The election of Ronald Reagan as president in 1980 heralded a significant rightward shift in American politics, reflected in major changes in taxation and spending priorities. His second term in office brought both the Iran-Contra scandal and significant diplomatic progress with the Soviet Union. The subsequent Soviet collapse ended the Cold War.

Contemporary era

The World Trade Center on the morning of September 11, 2001

Main articles: September 11 attacks, Iraq War, and Economic crisis of 2008

The leadership role taken by the United States and its allies in the UN–sanctioned Gulf War, under President George H. W. Bush, and the Yugoslav wars, under President Bill Clinton, helped to preserve its position as a superpower. The longest economic expansion in modern U.S. history—from March 1991 to March 2001—encompassed the Clinton administration and the dot-com bubble.⁴⁰ A civil lawsuit and sexual scandal led to Clinton's impeachment in 1998, but he remained in office. The 2000 presidential election, one of the closest in U.S. history, was resolved by a U.S. Supreme Court decision—George W. Bush, son of George H. W. Bush, became president.

On September 11, 2001, al-Qaeda terrorists struck the World Trade Center in New York City and The Pentagon near Washington, D.C., killing nearly three thousand people. In response, President Bush launched the War on Terrorism. In late 2001, U.S. forces led an invasion of Afghanistan, removing the Taliban government and al-Qaeda training camps. Taliban insurgents continue to fight a guerrilla war. In 2002, the Bush administration began to press for regime change in Iraq on controversial grounds.⁴¹ Lacking the support of NATO or an explicit UN mandate for military intervention, Bush organized a Coalition of the Willing; coalition forces preemptively invaded Iraq in 2003, removing President Saddam Hussein. The Iraq War, now opposed by most Americans, continues.⁴² Amnesty International has criticized the U.S. for human rights violations in its pursuit of the War on Terrorism and the Iraq War.⁴³ In 2005, Hurricane Katrina caused severe destruction along much of the Gulf Coast, devastating New Orleans. On November 4, 2008, amid a major economic crisis, the country elected Barack Obama as president. When he is inaugurated on January 20, 2009, he will become the first African American to hold the office.

Government and elections

Main articles: Federal government of the United States and Elections in the United States

The west front of the United States Capitol, which houses the United States Congress

The United States is the world's oldest surviving federation. It is a constitutional republic, "in which majority rule is tempered by minority rights protected by law."⁴⁴ It is fundamentally structured as a representative democracy, though U.S. citizens residing in the territories are excluded from voting for federal officials.⁴⁵ The government is regulated by a system of checks and balances defined by the U.S. Constitution, which serves as the country's supreme legal document and as a social contract for the American people. 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 and officials are elected by popular vote.

The South Portico of the White House, home and work place of the U.S. president

The federal government is composed 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 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.
• Judicial: The Supreme Court and lower federal courts, whose judges are appointed by the president with Senate approval, appoints, 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 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. The Senate has 100 members with each state having two senators, elected at-large to six-year terms; one third of Senate seats are up for election every other year. The president serves a four-year term and may be elected to the office no more than twice. The president is not elected by direct vote, but by an indirect electoral college system in which the determining votes are apportioned by state. The Supreme Court, led by the Chief Justice of the United States, has nine members, who serve for life. The state governments are structured in roughly similar fashion; Nebraska uniquely has a unicameral legislature. The governor (chief executive) of each state is directly elected.

The front of the United States Supreme Court building

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 judiciary is voided. The original text of the Constitution establishes the structure and responsibilities of the federal government and its relationship with the individual states. 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; the first ten amendments, which make up the Bill of Rights, and the Fourteenth Amendment form the central basis of Americans' individual rights.

Parties, ideology, and politics

Main articles: Politics of the United States and Political ideologies in the United States

President-elect Barack Obama (right) meets with current President George W. Bush (left) in the Oval Office, November 10, 2008

The United States has operated under a two-party system for most of its history. For elective offices at all levels, state-administered primary elections choose the major party nominees for subsequent general elections. Since the general election of 1856, the major parties have been the Democratic Party, founded in 1824, and the Republican Party, founded in 1854. 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% of the popular vote.

Within American political culture, the Republican Party is considered "center-right" or conservative and the Democratic Party is considered "center-left" or liberal. The states of the Northeast and West Coast and some of the Great Lakes states, known as "blue states", are relatively liberal. The "red states" of the South and much of the Great Plains and Rocky Mountains are relatively conservative. A plurality of Americans identify as Democrats, yet significantly more Americans identify as conservative than liberal.⁴⁶

The incumbent president, Republican George W. Bush, is the 43rd U.S. president. All presidents to date have been men of European descent. After winning the 2008 presidential election, Democrat Barack Obama will be the first president of mixed European and African descent. The 2008 elections also saw the Democratic Party strengthen its control of both the House and the Senate. Every member of the U.S. Congress is a Democrat or a Republican except two independent members of the Senate. An overwhelming majority of state and local officials are also Democrats or Republicans.

Geographic divisions

Main articles: U.S. state, Territorial evolution of the United States, and Territorial acquisitions of the United States

The United States is a federal union of fifty states. The original thirteen states were the successors of the thirteen colonies that rebelled against British rule. Most of the rest have been carved from territory obtained through war or purchase by the U.S. government. The exceptions are Vermont, Texas, and Hawaii; each was an independent republic before joining the union. Early in the country's history, three states were created out of the territory of existing ones: Kentucky from Virginia; Tennessee from North Carolina; and Maine from Massachusetts. West Virginia broke away from Virginia during the American Civil War. The most recent state—Hawaii—achieved statehood on August 21, 1959. The states do not have the right to secede from the union.

The states compose the vast bulk of the U.S. land mass; the two other areas considered integral parts of the country are the District of Columbia, the federal district where the capital, Washington, is located; and Palmyra Atoll, an uninhabited but incorporated territory in the Pacific Ocean. The U.S. also possesses five major overseas territories: Puerto Rico and the United States Virgin Islands in the Caribbean; and American Samoa, Guam, and the Northern Mariana Islands in the Pacific. Those born in the territories (except for American Samoa) possess U.S. citizenship.

Foreign relations and military

Main articles: Foreign policy of the United States and Military of the United States

President George W. Bush (right) with British Prime Minister Gordon Brown

The United States exercises global economic, political, and military influence. It is a permanent member of the United Nations Security Council and New York City hosts the United Nations Headquarters. 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, Sudan, and the Republic of China (Taiwan) do not have formal diplomatic relations with the United States.

The U.S. enjoys a special relationship with the United Kingdom 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 U.S. spent $27 billion on official development assistance, the most