USA

The United States of America is a federal constitutional democracy comprising fifty states and a federal region. The country is placed mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie among 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, and the state of Hawaii is in the mid-Pacific. The United States also acquires several territories, or narrow areas, that are spotted around the Caribbean and Pacific.

At 3.79 million square miles (9.83 million km²) and with over 300 million people, the United States is the third or fourth largest country by total area, and third largest by land area and by inhabitants. The United States is one of the world's most culturally diverse nations, the product of large-scale colonization from many countries. The U.S. economy is the largest national economy in the world, with a nominal 2006 gross domestic product (GDP) of more than US$13 trillion (over 19% of the world total).

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 insubordinate states defeated Britain in the American innovative War, the first successful colonial war of independence. A federal convention adopted the current United States creation on September 17, 1787; its agreement the following year made the states part of a single republic. The Bill of Rights, comprising ten lawful amendments, was ratified in 1791.