The war fought in the United States between northern (Union) and southern (Confederate) states from 1861 to 1865, in which the Confederacy sought to establish itself as a separate nation. The Civil War is also known as the War for Southern Independence and as the War between the States. The war grew out of deep-seated differences between the social structure and economy of North and South, most notably over slavery; generations of political maneuvers had been unable to overcome these differences (see Missouri Compromise and Compromise of 1850). The secession of the southern states began in late 1860, after Abraham Lincoln was elected president. The Confederacy was formed in early 1861. The fighting began with the Confederate attack on Fort Sumter. Most of the battles took place in the South, but one extremely crucial episode, the Battle of Gettysburg, was fought in the North. The war ended with the surrender of General Robert E. Lee to General Ulysses S. Grant at Appomattox Court House. (See Battle of Bull Run, Battle of Chancellorsville, Emancipation Proclamation, and Sherman's march to the sea; also see map, next page.)

Note: The Civil War has been the most serious test yet of the ability of the United States to remain one nation.