The United States of America developed into a republic from its colonial beginnings in the 16th century. Victory in the American Revolution (1775-1783), a conflict between the colonies and Great Britain, established the United States as an independent nation. The American Civil War, a military conflict between the United States of America and the Confederate States of America, took place from 1861 to 1865. In the next 150 years, the United States emerged as a global military and economic force.