The United States of America is a federal republic of fifty states, a federal district, and several territories.[8][9][10] It is commonly called the United States, the United States of America (shortened to U.S. and U.S.A.), and also sometimes just America.

The country is mostly in North America. There are forty-eight states that border each other and Washington, D.C., the capital district. These states are between the Pacific and Atlantic Oceans. They are 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 some territories, or insular areas, in the Caribbean and Pacific.

At 3.79 million square miles (9.83 million km2) and with about 327 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 mixed and multicultural nations, the product of large-scale immigration from many countries.[11] The U.S. economy is the largest national economy in the world, with an estimated 2016 gross domestic product (GDP) of US$20.4 trillion (about a quarter of worldwide GDP).[12]

The nation was founded by thirteen colonies of Great Britain along the Atlantic seaboard. On July 4, 1776, they issued the Declaration of Independence, which announced their independence from Great Britain and their creation of a cooperative union. The disobedient states defeated Great Britain in the American Revolutionary War, the first successful colonial war of independence.[13] The Philadelphia Convention adopted the current United States Constitution on September 17, 1787; its approval the following year made the states part of a single republic with a strong central government. The Bill of Rights, making up ten constitutional amendments guaranteeing many basic civil rights and freedoms, was approved in 1791.

In the 19th century, the United States got land from France, Spain, the United Kingdom, Mexico, and Russia, and took over the Republic of Texas and the Republic of Hawaii. Arguments between the farming-based South and industrial North over the growth of the institution of slavery and states' rights began 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 wealth was the world's largest.[14] The Spanish–American War and World War I confirmed the country's status as a military power. In 1945, the United States came out 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 and the breaking up of the Soviet Union left the United States as the only superpower. The country accounts for about half of worldwide military spending and is a leading economic, political, and cultural force in the world.[15]

The land area of the contiguous United States is 2,959,064 square miles (7,663,941 km2). Alaska, separated from the contiguous United States by Canada, is the largest state at 663,268 square miles (1,717,856 km2). Hawaii, occupying an archipelago in the central Pacific, southwest of North America, is 10,931 square miles (28,311 km2) in area.[16]

The United States is the world's third or fourth largest nation by total area (land and water), ranking behind Russia and Canada and 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 United States is measured: calculations range from 3,676,486 square miles (9,522,055 km2)[17] to 3,717,813 square miles (9,629,091 km2)[18] to 3,794,101 square miles (9,826,676 km2).[19] Measured by only land area, the United States is third in size behind Russia and China, just ahead of Canada.[20]

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 Chihuahua and Mojave. The Sierra Nevada and Cascade mountain ranges run close to the Pacific coast, both ranges reaching altitudes higher than 14,000 feet.

The United States, with its large size and geographical 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-dry. Much of the Western mountains are alpine. The climate is dry 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 unusual—the states bordering the Gulf of Mexico are prone to hurricanes, and most of the world's tornadoes happen within the country, mainly in the Midwest's Tornado Alley.[21]

The U.S. ecology is considered "megadiverse": about 17,000 species of vascular plants occur in the contiguous United States and Alaska, and over 1,800 species of flowering plants are found in Hawaii, few of which occur on the mainland.[22] The United States is home to more than 400 mammal, 750 bird, and 500 reptile and amphibian species.[23] About 91,000 insect species have been described.[24]

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.[25] Altogether, the government owns 28.8% of the country's land area.[26] Most of this is protected, though some is leased for oil and gas drilling, mining, logging, or cattle ranching; 2.4% is used for military purposes.[26]

It is believed that the indigenous peoples of the continental United States, including the natives of Alaska, moved in from Asia. They began arriving twelve or forty thousand years ago, if not earlier.[27] Some, such as the pre-Columbian Mississippian culture in the southeast, developed advanced farming, grand construction, and state-level communities. The native population of America decreased after Europeans arrived, and for different reasons, mostly sicknesses such as smallpox and measles.[28]

In 1492, Genoese explorer Christopher Columbus, under contract to the Spanish crown, reached some Caribbean islands, making the first contact with the native people. On April 2, 1513, Spanish conquistador Juan Ponce de León landed on what he called "La Florida"—the first recorded European coming on what would become the U.S. mainland. Spanish settlements in the area were followed by ones in the present-day southwestern United States that 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 Colony of Virginia in Jamestown in 1607 and the Pilgrims' Plymouth Colony in 1620. The 1628 chartering of the Massachusetts Bay Colony resulted in a wave of relocation; 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.[29] Beginning in 1614, the Dutch settled along the lower Hudson River, including New Amsterdam on Manhattan Island.

Tensions between American colonials and the British during the rebel 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, meeting in Philadelphia, established a Continental Army under the command of George Washington. Announcing that "all men are created equal" and are born with "certain natural rights," the Congress adopted the Declaration of Independence, drafted mostly by Thomas Jefferson, on July 4, 1776. That date is now celebrated every year 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 helped by the French, Great Britain recognized the independence of the United States and the states' sovereignty over American land 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 approved 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 certifying 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 permanently stopped 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 different social reform movements, including abolitionism.

Americans' eagerness to expand westward caused 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 land under President Thomas Jefferson in 1803 almost doubled the nation's size. The War of 1812, declared against Britain over different complaints and fought to a draw, strengthened U.S. nationalism. A series of U.S. military invasions into Florida led Spain to give up it and other Gulf Coast territory in 1819. The United States took over the Republic of Texas in 1845. The idea of Manifest destiny became popular during this time.[30] 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 encouraged western relocation. 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 murdered for skins and meat and to ease the railways' spread. The loss of the buffalo, which were valuable to the plains Indians, caused many native cultures to become gone forever.

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, a candidate of the mostly 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 end slavery. Following the Union victory in 1865, three changes to the U.S. Constitution secured freedom for the nearly four million African Americans who had been slaves,[31] made them citizens, and gave them voting rights. The war and its resolution led to a big increase in federal power.[32]

After the war, the assassination of Abraham Lincoln caused the Reconstruction, where policies were put together directed at getting back and rebuilding the Southern states while securing the rights of the newly freed slaves. The resolution of the disputed 1876 presidential election by the Compromise of 1877 ended this era, and the Jim Crow laws soon disenfranchised many African Americans. In the North, urbanization and a never-before-seen inflow of immigrants from Southern and Eastern Europe made the country's industrialization grow rapidly. The wave of immigration, lasting until 1929, gave labor and changed American culture. High tax protections, national infrastructure building, and new banking laws encouraged growth also. 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 native monarchy of the Pacific Kingdom of Hawaii was ended in a secret and successful plan led by American residents; the United States took over the archipelago in 1898. Victory in the Spanish–American War the same year proved that the United States was a world power and led to the addition of Puerto Rico, Guam, and the Philippines. The Philippines gained independence fifty years later; Puerto Rico and Guam are still U.S. territories.

As the First World War erupted in Europe in 1914, the United States declared itself neutral. Afterward, the Americans sympathized with the British and French, even though many citizens, especially those from Ireland and Germany, were against the intervention.[33] In 1917, they joined the Allies, adding to the defeat of the Central Powers. Unwilling to participate in European affairs, the Senate did not approve the Treaty of Versailles (1919), which established the League of Nations, applying a policy of unilateralism, which bordered on isolationism.[34] In 1920, the Women's rights movement gained the approval of a constitutional amendment to grant women the right to vote.[35]

For most of the 1920s, the country enjoyed a period of success, decreasing the inequality in the balance of payments while profiting from industrial farms. This period, known as 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 series of policies that increased government interference in the economy.[36] From 1920 to 1933 a prohibition banning alcohol was in place.[37] The Dust Bowl of the 1930s left many poor farmer communities and encouraged a new wave of emigration to the West Coast.[38]

The United States, officially neutral during the early stages of World War II, began supplying supplies to the Allies in March 1941, through the Lend-Lease program. On December 7, 1941, the country joined the Allies fight against the Axis Powers, after the Japanese attack on Pearl Harbor. World War II boosted the economy by providing investment capital and jobs, making many women enter the labor market. Of the significant fighters, the United States was the only nation to be enriched by war.[39] The discussions at Bretton Woods and Yalta created a new system of international organization that placed the country and the Soviet Union at the heart of world affairs. In 1945, when the end of the Second World War in Europe came, an international gathering held in San Francisco drafted the Charter of the United Nations, which came into force after the war.[40] Having developed the first nuclear weapon, the government decided to use it in the Japanese cities of Hiroshima and Nagasaki in August of that same year. Japan gave up on September 2, ending the war.[41]

In the Cold War, the United States and the Soviet Union competed after the Second World War, controlling the military affairs of Europe through NATO and the Warsaw Pact. The first supported liberal democracy and capitalism, while the second favored communism and an economy planned by the government. Both supported several dictatorships and participated in proxy wars. Between 1950 and 1953, U.S. troops fought Chinese communist forces in the Korean War.[42] From the break with the USSR and the start of the Cold War until 1957, McCarthyism also called the Second Red Dread, developed within the United States. The State unleashed a wave of political mistreatment and a campaign of prejudice against Communists, which some authors point out as of a totalitarian state. Hundreds of people were arrested, including celebrities, and between 10,000 and 12,000 people lost their jobs.[43] The abuse ended when the courts declared it unconstitutional.[44]

In 1961, the Soviet launch of the first human-crewed spacecraft caused President John F. Kennedy to propose to the country to be the first to send "a man to the Moon", a fact completed in 1969.[45] Kennedy also faced a tense nuclear conflict with the Soviet forces in Cuba, while the economy grew and expanded steadily. A growing movement for civil rights, represented and led by African-Americans such as Rosa Parks, Martin Luther King, Jr. and James Bevel, used nonviolence to deal with segregation and discrimination.[46] After Kennedy's murder in 1963, the Civil Rights Act of 1964 and the Voting Rights Act of 1965 were passed during the term of President Lyndon B. Johnson. Johnson and his successor, Richard Nixon, led a civil war in Southeast Asia, assistant to the unsuccessful Vietnam War. A generalized counterculture movement grew, driven by opposition to war, black nationalism and the sexual revolution. A new wave of feminist movements also emerged, led by Betty Friedan, Gloria Steinem and other women who sought political, social and economic equity.

In 1974, as a result of the Watergate scandal, Nixon became the first president to resign, to avoid being dismissed on charges such as obstruction of justice and abuse of power, and was succeeded by Vice President Gerald Ford.[47] The presidency of Jimmy Carter in the 1970s was marked by stagflation and the hostage crisis in Iran. The election of Ronald Reagan as president in 1980 announced a change in U.S. policy, which was reflected in significant changes in taxes and fiscal expenses. His second term brought with it the Iran–Contra affair and the significant diplomatic progress with the Soviet Union. The later Soviet collapse ended the Cold War.

Under President George H. W. Bush, the country took on a global dominant role worldwide, as in the Gulf War (1991). The longest economic expansion in modern American history, from March 1991 to March 2001, spanned the presidency of Bill Clinton and the dot-com bubble.[48] A civil lawsuit and a sex scandal led to his impeachment in 1998, although he managed to finish his period. The 2000 presidential elections, one of the most competitive in American history, they were settled by the Supreme Court: George W. Bush, son of George H. W. Bush, became president, even though he gained fewer votes than his opponent Al Gore.[49]

On September 11, 2001, the terrorists of the Al-Qaeda group attacked the twin towers of the World Trade Center in New York City (which were destroyed) and the Pentagon near Washington, D.C., in a series of attacks that ended the life of nearly three thousand people. In response, the Bush administration launched the "War on Terror." At the end of 2001, U.S. forces invaded Afghanistan, toppled the Taliban government and destroyed Al-Qaeda's training camps. Taliban insurgents continue to fight a guerrilla war. In 2002, Bush began to push for a regime change to take place in Iraq.[50][51] With NATO's lack of support and without a clear UN order for military intervention, Bush organized the coalition of the willing; The coalition forces quickly invaded Iraq in 2003 and toppled the statue of dictator Saddam Hussein. The following year, Bush was re-elected as the most voted president in an election.

In 2005, Hurricane Katrina, which would end up being the deadliest natural disaster in national history, caused severe destruction along the Gulf Coast: the city of New Orleans was devastated, with 1833 dead.[52]

On November 4, 2008, during a global economic downturn, Barack Obama was elected president, having been the first African American to take office. In May 2011, American Special forces managed to kill Osama bin Laden, hiding in Pakistan. The following year, Barack Obama was re-elected. Under his second term, he led the war against the Islamic State and restored diplomatic relations with Cuba.

On November 8, 2016, the Republican Party leader Donald Trump defeated former First Lady Hillary Clinton for presidency in an unusual election and whose plans have been described by political analysts as populist, protectionist and nationalist, assuming office on January 20, 2017.[53]

The massacres in Orlando of June 12, 2016 at the gay disco Pulse (51 dead) and in Las Vegas on October 1, 2017 (60) are listed as the largest massacres in the country since 9/11.[54]

The United States is the world's oldest surviving federation. It is a constitutional republic and representative democracy, "in which majority rule is tempered by minority rights protected by law."[55] The government is controlled by a system of checks and balances from the United States Constitution. The constitution is the country's main legal document. There are three branches. They are the executive branch, the legislative branch, and the judicial branch. State governments and the federal government work in very similar ways. Each state has its own executive, legislative, and judicial branches. The executive branch of a state government is led by a governor, instead of a president.

The executive branch is the part of the government that enforces the law.  Members of the U.S. Electoral College elect a president who is the leader of the executive branch, as well as the leader of the armed forces. The president may veto a bill that the Congress has passed, so it does not become a law. The President may also make "executive orders" to ensure that people follow the law.

The president is in charge of many departments that control much of the day-to-day actions of government. For example, Department of Commerce makes rules about trade.  The president chooses the heads of these departments, and also nominates federal judges.  However, the Senate, part of the legislative branch, must agree with all of the people the president chooses. The president may serve two 4-year terms.

The legislative branch makes laws. The legislative branch is called the United States Congress. Congress is divided into two "houses".

One house is the House of Representatives.  The Representatives are each elected by voters from a set area within a state.  The number of Representatives a state has is based on how many people live there.  Representatives serve two-year terms. The total number of representatives today is 435. The leader of the House of Representatives is the Speaker of the House.

The other house is the Senate. In the Senate, each state is represented equally, by two senators. Because there are 50 states, there are 100 senators.  The President's treaties or appointments of officials need the Senate's approval. Senators serve six-year terms. The Vice President of the United States serves as president of the Senate.  In practice, the vice president is usually absent from the Senate, and a senator serves as president pro tempore, or temporary president, of the Senate.

Representatives and senators propose laws, called "bills", in their respective houses. A bill may be voted upon by the entire house right away or may first go to a small group, known as a committee, which may recommend a bill for a vote by the whole house. If one house votes to pass a bill, the bill then gets sent to the other house; if both houses vote for it, it is then sent to the president, who may sign the bill into law or veto it. If the president vetoes the bill, it is sent back to Congress. If Congress votes again and passes the bill with at least a two-thirds majority, the bill becomes law and cannot be vetoed by the president.

Under the American system of federalism, Congress may not make laws that directly control the states; instead, Congress may use the promise of federal funds, or special circumstances such as national emergencies, to encourage the states to follow federal law. This system is both complex and unique.

The judicial branch is the part of government that interprets what the law means. The Judicial Branch is made up of the Supreme Court and many lower courts. If the Supreme Court decides that a law is not allowed by the Constitution, the law is said to be "struck down" and is no longer a valid law.

The Supreme Court is made up of nine judges, called justices, who are nominated by the President and confirmed by the Senate. One of these justices, called the chief justice, heads the court. A Supreme Court justice serves until he or she dies or resigns (quits in the middle of his or her term). When that happens, the president nominates someone new to replace the justice who left. If the Senate agrees with that choice, the person becomes a justice. If the Senate does not agree with the president's choice, then the president must nominate someone else.

Famous court cases such as Marbury v Madison (which was decided in 1803) have firmly established that the Supreme Court is the ultimate interpreter of the United States Constitution and has the power to strike down any law that conflicts with it.[56]

The United States of America consists of 50 states, 5 territories and 1 district (Washington D.C.). States can make laws about things inside the state, but federal law is about things dealing with more than one state or dealing with other countries. In some areas, if the federal government makes laws that say different things from the state laws, people must follow the federal law because the state law is not a law any more. Each state has a constitution of its own, different from the federal (national) Constitution. Each of these is like the federal Constitution because they say how each state's government is set up, but some also talk about specific laws.

The federal and most state governments are dominated by two political parties: the Republicans and the Democrats. There are many smaller parties; the largest of these are the Libertarian Party and the Green Party. People help in political campaigns that they like. They try to persuade politicians to help them; this is called lobbying. All Americans are allowed to do these things, but some have and spend more money than others, or in other ways do more in politics. Some people think this is a problem, and lobby for rules to be made to change it.

Since 2017, the president is a Republican, and Congress is also Republican-controlled, so the Republicans have more power in the federal government.  There are still many powerful Democrats who can try to stop the Republicans from doing things that they believe will be bad for the country. Also, members of a party in power do not always agree on what to do. If enough people decide to vote against Republicans in the next election, they will lose power. In a republic like the United States, no party can do whatever they want. All politicians have to argue, compromise, and make deals with each other to get things done. They have to answer to the people and take responsibility for their mistakes.

The USA's large cultural, economic, and military influence has made the foreign policy of the United States, or relations with other countries, a topic in American politics, and the politics of many other countries.

The United States conquered and bought new lands over time, and grew from the original 13 colonies in the east to the current 50 states, of which 48 of them are joined together to make up the contiguous United States. These states, called the "lower 48", can all be reached by road without crossing a border into another country. They go from the Atlantic east to the Pacific in the west. There are two other states which are not joined to the lower 48 states. Alaska can be reached by passing through British Columbia and the Yukon, both of which are part of Canada. Hawaii is in the middle of the Pacific Ocean.

Washington, D.C., the national capital, is a federal district that was split from the states of Maryland and Virginia in 1791. Not part of any US state, it used to be in the shape of a square, with the land west of the Potomac River coming from Virginia, and the land east of the river coming from Maryland. In 1846, Virginia took back its part of the land. Some people living in DC want it to become a state, or for Maryland to take back its land, so that they can have the right to vote in Congress.

The United States consists of sixteen lands that are not states, many of which are colonial territories. None of them have any land borders with the rest of the US. People live in five of these places, which are de facto American:

The Philippines was a possession of the United States. Palau, the Federated States of Micronesia, and other Pacific island nations were governed by the United States as a United Nations "Trust Territory". All of these places have become independent: the Philippines in 1946, Palau in 1947, and Micronesia in 1986.

The U.S. armed forces has bases in many countries, and the U.S. Navy's base at Guantanamo Bay was rented from Cuba after that country had a Communist revolution.

All the states are divided into administrative subdivisions. Most of them are called counties, but Louisiana uses the word "parish," and Alaska uses the word "borough."

There are many cities in the United States. One city in each state is the state capital, where the government of the state meets and the governor works. This city is not always the largest in its state. For example, the city with the most people living in it is New York City in New York State, but the state capital is Albany. Some other big cities are Los Angeles, California; Chicago, Illinois; Seattle, Washington; Miami, Florida; Indianapolis, Indiana; Las Vegas, Nevada; Houston and Dallas, Texas; Philadelphia and Pittsburgh, Pennsylvania; Boston, Massachusetts; Denver, Colorado; St. Louis, Missouri and Detroit, Michigan.

The United States is very influential in global economics, politics, and the military. It is a permanent member of the United Nations Security Council and the headquarters of the United Nations is in New York City. It is a member of the G7,[57] G20, and Organisation for Economic Co-operation and Development. Almost all countries have embassies in Washington, D.C., and many have consulates around the country. Likewise, nearly all nations host American diplomatic missions. However, Iran, North Korea, Bhutan, and Taiwan do not have formal diplomatic relations with the United States. The United States has a "special relationship" with the United Kingdom[58] and strong ties with Canada,[59] Australia,[60] New Zealand,[61] Japan,[62] South Korea,[63] and Israel.[64]

The president is the commander-in-chief of the country'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, Marine Corps, Navy, and Air Force. The Coast Guard is run by the Department of Homeland Security in peacetime and by the Department of the Navy during times of war. In 2008, the armed forces had 1.4 million personnel on active duty, along with several hundred thousand each in the Reserves and National Guard for a total of 2.3 million troops. The Department of Defense also employed about 700,000 civilians, not including contractors.[65]

The military budget of the United States in 2011 was more than $700 billion, 41% of global military spending and equal to the next 14 largest national military expenditures combined. At 4.7% of GDP, the rate was the second-highest among the top 15 military spenders, after Saudi Arabia.[66] U.S. defense spending as a percentage of GDP ranked 23rd globally in 2012 according to the CIA.[67] The proposed base Department of Defense budget for 2012, $553 billion, was a 4.2% increase over 2011; an additional $118 billion was proposed for the military campaigns in Iraq and Afghanistan.[68] The last American troops serving in Iraq departed in December 2011;[69] 4,484 service members were killed during the Iraq War.[70] Approximately 90,000 U.S. troops were serving in Afghanistan in April 2012;[71] by November 8, 2013 2,285 had been killed during the War in Afghanistan.[72]

The United States has a capitalist economy. The country has rich mineral resources, with many gold, coal and uranium deposits. Farming makes the country among the top producers of, among others, corn (maize), wheat, sugar, and tobacco. Housing contributes about 15% to the Gross Domestic Product (GDP) of  the United States[73]America produces cars, airplanes, and electronics. About 3/4 of Americans work in the service industry.

The United States of America has people of many different race and ethnic backgrounds. 80% of the people in the United States descend from European immigrants. Many people are descended from Germany, England, Scotland, Ireland, Africa, and Italy.[74]  13% of the people in the United States are African-American. Most of them descend from the African slaves that were brought to America. Asian-Americans make up only 5% of the population in America but make up a bigger portion in the west coast. For example, in California, Asian-Americans make up 13% of the population of that state. Hispanic-Americans or people of Latin origins make up 15% of the nation. The original peoples, called Native American, American Indians, or Amerindians and Inuit (Eskimos) are a very small group.

11% of the people in the United States are foreign born. 18% speak a language other than English at home. For people 25 and older, 80% are high school graduates while 25% have a bachelor's degree or higher.

The 2000 Census counted self-reported ancestry. It identified 43 million German-Americans, 30.5 million Irish-Americans, 24.9 million African-Americans, 24.5 million English-Americans, and 18.4 million Mexican-Americans.

The social structure of the United States has a big range. This means that some Americans are much, much richer than others. The average (median) income for an American was $37,000 a year in 2002. However, the richest 1% of Americans have as much money as the poorest 90%. 51% of all households have access to a computer and 41% had access to the Internet in 2000, a figure which had grown to 75% in 2004. Also, 67.9% of American families owned their homes in 2002.  There are 200 million cars in the United States, two for every three Americans. The debt has grown to over $21,000,000,000,000.

There are many different religions in the U.S.  Statistically, the largest religion is Christianity, including groups such as Catholicism, Protestantism and Mormonism. Other religions include Hinduism, Islam, Judaism, Unitarian Universalism, Wicca, Druidry, Baha'i, Raelism, Zoroastrianism, Taoism and Jainism.[75] Religions which were founded within the United States include Eckankar, Satanism and Scientology.  Native American religions have various animistic beliefs.

The United States is one of the most religious countries in the Western World, and most Americans believe in God. The number of Christians in the U.S. has gone down. 86.2% called themselves Christian in 1990 and 78.4% said this in 2007. The others include Judaism (2.3%), Islam (0.8%), Buddhism (0.7%), Hinduism (0.4%), and Unitarian Universalism (0.3%). Those who have no religion are at 16.1%. There is a large difference between those who say that they belong to a religion and those who are members of a religious body of that religion.[76]

Doubts about the existence of a God, gods or goddesses are higher among young people.[77] Among the non-religious population of the U.S., there are deists, humanists, ignotic, atheists, and agnostics.[78]

English (American English) is the de facto national language. Although there is no official language at the federal level, some laws—such as U.S. naturalization requirements—standardize English. In 2010, about 230 million, or 80% of the population aged five years and older, spoke only English at home. Spanish, spoken by 12% of the population at home, is the second most common language and the most widely taught second language.[79][80] Some Americans advocate making English the country's official language, as it is in at least twenty-eight states. Both Hawaiian and English are official languages in Hawaii by state law.[81]

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.[82] Other states, such as California, order the publication of Spanish versions of certain government documents including court forms.[83] Many jurisdictions with large numbers of non-English speakers produce government materials, especially voting information, in the most commonly spoken languages in those jurisdictions.

Several insular territories grant official recognition to their native languages, along with English: Samoan and Chamorro are recognized by American Samoa and Guam, respectively; Carolinian and Chamorro are recognized by the Northern Mariana Islands; Spanish is an official language of Puerto Rico and is more widely spoken than English there.

In most states, children are required to attend school from the age of six or seven (generally, kindergarten or first grade) until they turn eighteen (generally bringing them through twelfth grade, the end of high school); some states allow students to leave school at sixteen or seventeen.[84] About 12% of children are enrolled in parochial or nonsectarian private schools. Just over 2% of children are homeschooled.[85]

American popular culture goes out to many places in the world. It has a large influence on most of the world, especially the Western world. American music is heard all over the world, and American movies and television shows can be seen in most countries.

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The American flag is made up of 50 stars on a blue background, and has 13 stripes, seven red and six white. It is one of many symbols of the United States like the Bald Eagle. The 50 stars represent the 50 states. The red stands for courage. The blue stands for justice. The white represents peace and cleanliness. The 13 stripes represent the 13 original colonies.[87]

LawConstitutionBill of RightsSeparation of powers

EnforcementDepartment of Justice (DoJ)Federal Bureau of Investigation (FBI)

LegislatureHouseSenate

ExecutiveCabinetFederal agenciesForeign policy

JudiciarySupreme CourtAppeals

IntelligenceCentral Intelligence Agency (CIA)Defense Intelligence Agency (DIA)National Security Agency (NSA)

MilitaryArmyMarine CorpsNavyAir ForceCoast Guard