The United States of America is a federal constitutional
republic comprising fifty states and a federal district. The
country is 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 the 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 in the Pacific and Caribbean.
Indigenous peoples of Asian origin have inhabited what is now the
mainland United States for many thousands of years. This Native
American population was greatly reduced by disease and warfare
after European contact. The United States was founded by thirteen
British colonies located along the Atlantic seaboard. On July 4,
1776, they issued the Declaration of Independence, which proclaimed
their right to self-determination and their establishment of a
cooperative union. The rebellious states defeated the British
Empire in the American Revolution, the first successful colonial
war of independence.[8] The current United States Constitution was
adopted 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.