USA

The United States of America

The United States of America (USA or U.S.A.), commonly referred to as the United States (US or U.S.), America, and sometimes the States, is a federal republic consisting of 50 states and a federal district. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. The state of Alaska is the northwestern part of North America and the state of Hawaii is an archipelago in the mid-Pacific. The country also has five populated and nine unpopulated territories in the Pacific and the Caribbean.

At 3.8 million square miles (9.8 million km²) and with around 318 million people, the United States is the world's third- or fourth-largest country by total area and third-largest by population.

The United States emerged from 13 British colonies located along the Atlantic seaboard.

The first publicly published evidence of the phrase "United States of America" was in an anonymously written essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776.

The first North American settlers migrated from Siberia by way of the Bering land bridge approximately 15,000 or more years ago.

Americans' eagerness to expand westward prompted a long series of Indian Wars.

From the beginning of the United States, inherent divisions over slavery between the North and the South in American society ultimately led to the American Civil War.

After World War II the United States and the Soviet Union jockeyed for power during what is known as the Cold War, driven by an ideological divide between capitalism and communism.

Geography and climate

The United States, 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.

Population

The U.S. population almost quadrupled during the 20th century, from about 76 million in 1900. The third most populous nation in the world, after China and India, the United States is the only major industrialized nation in which large population increases are projected.

The United States has a very diverse population. German Americans are the largest ethnic group (more than 50 million).

White Americans are the largest racial group; Black Americans are the nation's largest racial minority and third largest ancestry group.Asian Americans are the country's second largest racial minority; the three largest Asian American ethnic groups are Chinese Americans, Filipino Americans, and Indian Americans.

Nine cities had more than one million residents.

Four global cities had over two million (New York City, Los Angeles, Chicago, and Houston).

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.

In a 2013 survey, 56% of Americans said that religion played a "very important role in their lives", a far higher figure than that of any other wealthy nation. By contrast, religion plays the least important role in New England and in the Western United States.

In 2008, the armed forces had 1.4 million personnel on active duty.

The last American troops serving in Iraq departed in December 2011; 4,484 service members were killed during the Iraq War. By November 8, 2013 2,285 had been killed during the War in Afghanistan.

The United States has the highest rate of per-capita vehicle ownership in the world, with 765 vehicles per 1,000 Americans.

As of April 2010, 77% of American households owned at least one computer, and 68% had broadband Internet service. 85% of Americans also own a mobile phone as of 2011.

Of Americans 25 and older, 84.6% graduated from high school, 52.6% attended some college, 27.2% earned a bachelor's degree, and 9.6% earned graduate degrees.

The United States has a life expectancy of 78.4 years at birth, up from 75.2 years in 1990.