Britain's American colonies broke with the mother country in 1776 and were recognized as the new nation of the United States of America following the Treaty of Paris in 1783. During the 19th and 20th centuries, 37 new states were added to the original 13 as the nation expanded across the North American continent and acquired a number of overseas possessions. The two most traumatic experiences in the nation's history were the Civil War (1861-65) and the Great Depression of the 1930s. Buoyed by victories in World Wars I and II and the end of the Cold War in 1991, the US remains the world's most powerful nation state. The economy is marked by steady growth, low unemployment and inflation, and rapid advances in technology.
Location: North America, bordering both the North Atlantic Ocean and the North Pacific Ocean, between Canada and Mexico
Area: total: 9,826,630 sq km land: 9,161,923 sq km water: 664,707 sq km note: includes only the 50 states and District of Columbia
Area - Comparative: about half the size of Russia; about three-tenths the size of Africa; about half the size of South America (or slightly larger than Brazil); slightly larger than China; more than twice the size of the European Union
Climate: mostly temperate, but tropical in Hawaii and Florida, arctic in Alaska, semiarid in the great plains west of the Mississippi River, and arid in the Great Basin of the southwest; low winter temperatures in the northwest are ameliorated occasionally in January and February by warm chinook winds from the eastern slopes of the Rocky Mountains
Government Type: Constitution-based federal republic; strong democratic tradition
Capital: Washington, DC
Independence: 4 July 1776 (from Great Britain)
Legal System: federal court system based on English common law; each state has its own unique legal system, of which all but one (Louisiana, which is still influenced by the Napoleonic Code) is based on English common law; judicial review of legislative acts; has not accepted compulsory ICJ jurisdiction
Industries: leading industrial power in the world, highly diversified and technologically advanced; petroleum, steel, motor vehicles, aerospace, telecommunications, chemicals, electronics, food processing, consumer goods, lumber, mining
Military Branches: Army, Navy and Marine Corps, Air Force, and Coast Guard; note - Coast Guard administered in peacetime by the Department of Homeland Security, but in wartime reports to the Department of the Navy
Military Service and Obligations: 18 years of age; 17 years of age with written parental consent (2006)
Manpower Available for Military Service: males age 18-49: 67,742,879 females age 18-49: 67,070,144 (2005 est.)
Military Expenditures - Percent of GDP: 4.06% (2005 est.)
