The American Civil War took place from 1861 through 1865. It was the deadliest war in United States history, with about 2% of the population being killed.
The American Civil War took place between the Union, or Northern States, and the Confederacy, or Southern States. After the election of President Abraham Lincoln , the Southern States seceded, or broke away from the United States and created their own nation. These Southern States became known as the Confederate States of America and elected Jefferson Davis as President. When the Confederacy surrendered in 1865, and eventually rejoined the United States of America.