In 1776, the United States declared its independence. Led by General George Washington, it won the Revolutionary War in 1783. The Constitution was adopted in 1789, and a Bill of Rights was added in 1791 to guarantee inalienable rights. Washington, the first president, and his adviser Alexander Hamilton created a strong central government. The Louisiana Purchase in 1803 doubled the size of the country. Encouraged by available, inexpensive land and the notion of manifest destiny, the country expanded to the Pacific Coast. The resulting expansion of slavery was increasingly controversial. After the election of Abraham Lincoln as president in 1860, the southern states seceded to form the pro-slavery Confederate States of America, and started the Civil War. The Confederates' defeat in 1865 led to the abolition of slavery. In the subsequent Reconstruction era, the national government gained explicit duty to protect individual rights. White southern Democrats regained their political power in the South in 1877, often using paramilitary suppression of voting and Jim Crow laws to maintain white supremacy.