the territory now part of the united states has been inhabited for from 15,000 to 40,000 years, as attested by local evidence. the aboriginal peoples, ancestral to todays american indians, left no firm monuments on the scale of contemporaneous cultures elsewhere, but both the pueblos of the southwest and the great mounds of the mississippi river valley antedate the arrival of the european colonial powers. the original 13 british colonies that became the united states of america in 1776 were just one of several attempts by european powers to build empires in north america. all seized land from the native indians, who then were usually either assimilated or driven off by superior european weapons. the spaniards reached florida as early as 1513 and new mexico in 1540. the french began their exploration of the mississippi river valley in 1673. the russians reached alaska in 1741.
of all the colonizers, the british were the most successful. in 1607 jamestown became the first pe...