President Lincoln issues the Emancipation Proclamation. This order grants freedom only to those slaves residing in the states that have left the U.S., called the "Confederacy." But the Confederate states refuse to acknowledge Lincoln's order. They obey only the president they elected in 1862, Jefferson Davis.

After the Civil War ends, former Confederate states must agree to end slavery to be re-admitted into the United States. By December 18, 1865, the required three-quarters of the states had agreed to the Thirteenth Amendment to the United States Constitution, which ensured that forever after "neither slavery nor involuntary servitude ... shall exist within the United States."