The United States is the world's third largest country in population and the fourth largest country 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.
More than 75% of the United States population are urban (and as of the late 1990s more than 50% are estimated to be suburban, a not strictly defined category that can be taken as a subset of urban), and the great majority of the inhabitants are of European descent.
The mineral and agricultural resources of the United States are tremendous. Although the country was virtually self-sufficient in the past, increasing consumption, especially of energy, continues to make it dependent on certain imports. It is, nevertheless, the world's largest producer of both electrical and nuclear energy. It leads all nations in the production of liquid natural gas, aluminum, sulfur, phosphates, and salt. It is also a leading producer of copper, gold, coal, crude oil, nitrogen, iron ore, silver, uranium, lead, zinc, mica, molybdenum, and magnesium.
Major U.S. exports include motor vehicles, aircraft, food, iron and steel products, electric and electronic equipment, industrial and power-generating machinery, chemicals, and consumer goods. Leading imports include ores and metal scraps, petroleum and petroleum products, machinery, transportation equipment (especially automobiles), and paper and paper products. The major U.S. trading partners are Canada (in the world's largest bilateral trade relationship), Mexico, Japan, the United Kingdom, South Korea, and Germany. The volume of trade has been steadily increasing. The gross domestic product has continued to rise, and in 1998 it was easily the largest in the world at about $8.5 trillion. The development of the economy has been spurred by the growth of a complex network of communications not only by railroad, highways, inland waterways, and air but also by telephone, radio, television, computer (including the Internet), and fax machine.