when was the us founded as a country
United States Paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago.[25] European colonization began in the 16th century. The United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the colonies following the Seven Years' War led to the American Revolution, which began in 1775, and the subsequent Declaration of Independence in 1776. The war ended in 1783 with the United States becoming the first country to attain independence from a European power.[26] The current constitution was adopted in 1788. The first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties.