Europe showed little interest in the region until the 17th century when settlers, mainly religious dissidents, came from Britain. The trade rivalry between the colonists and Britain led to the Declaration of Independence by the 13 British colonies in 1776. US independence was recognized by Britain in 1782. Political and ideological differences led to the Civil War (1861-65), in which the northern states were victorious over the South. The following fifty years saw the US move from an agrarian to an industrial society. The persecution and extermination of the indigenous Americans culminated in the massacre of some 200 Oglala Sioux at Wounded Knee in 1890. During the 20th century the USA has become the major world power, both politically and economically.
The federal government of the 50 states of the US resides in the District of Columbia, a federal district not belonging to a state. The federal government is responsible for defence, foreign policy, economy, security, and federal justice. The president is head of state and commander-in-chief of the army; he appoints ministers with approval of Congress, the legislative power. This has two chambers, the 435-member House of Representatives, elected every two years, and the 100-member Senate. Senators are elected for a 6-year term, with elections held every 2 years for a third of their number.
