United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world’s third largest country in population and in area. It consists of 50 states and a federal district. The conterminous (excluding Alaska and Hawaii) United States stretches across central North America from the Atlantic Ocean on the east to the Pacific Ocean on the west, and from Canada on the north to Mexico and the Gulf of Mexico on the south. The state of Alaska is located in extreme NW North America between the Arctic and Pacific oceans and is bordered by Canada on the east. The state of Hawaii, an island chain, is situated in the E central Pacific Ocean c.2,100 mi (3,400 km) SW of San Francisco. Washington, D.C., is the capital of the United States, and New York is its largest city.
The outlying territories and areas of the United States include: in the Caribbean Basin, Puerto Rico (a commonwealth associated with the United States) and the Virgin Islands of the United States (purchased from Denmark in 1917); in the Pacific Ocean, Guam (ceded by Spain after the Spanish-American War), the Northern Mariana Islands (a commonwealth associated with the United States), American Samoa, Wake Island, and several other islands. The United States also has compacts of free association with the Republic of the Marshall Islands, the Republic of Palau, and the Federated States of Micronesia.