During the American Civil War, several states seceded from the United States of America (the "Union") to form the Confederate States of America. Also known as the Confederate States or Confederacy, it was made up of southern states and territories that had set up a de facto government led by Confederate President Jefferson Davis. In all, 11 southern states seceded from the Union, and the Confederacy lasted the duration of the Civil War, from 1861 to 1865.
While there were many causes for the rift between the Union and the Confederacy, the primary cause was the disagreement between the two governments over the issue of slavery. The southern states wanted to continue allowing the practice, while the northern states did not. Other issues, such as states' rights and taxes and tariffs, were also major sources of tension, however. As the relationship between the Northern and the Southern states grew more and more difficult, seven Southern states decided to separate from the Union. This occurred before Abraham Lincoln took office, but four more seceded after his tenure began.
The Confederate States of America officially folded when the Confederate Army surrendered in April 1865. Until that time, however, a battle raged between the Union and Confederate armies because the Union — or what was left of the United States of America — did not recognize the Confederacy as an independent nation. President Abraham Lincoln led the Union cause, and for the duration of his presidency, the two sides struggled — as President Lincoln put it — as a nation divided.
After the Civil War ended and the Confederate States of America was abolished, the states that attempted to secede were granted representation once again in Congress in an effort to bring the country together. Freed slaves who fought for the Union, known as Freedmen, were temporarily granted the right to vote, but their civil rights struggle would continue over the course of the next century.