On December 20, 1860, South Carolina became the first state to vote for secession from the United States of America. By the middle of May 1861, a total of eleven states had adopted ordinances of secession. In February 1861, the seceding states held a convention in Montgomery, Alabama, at which a provisional constitution was adopted and Jefferson Davis was chosen provisional President. A permanent Constitution was ratified on March 11, 1861. Interestingly enough, the Confederate Constitution prohibited the African slave trade but allowed interstate commerce in slaves.

In addition to the above eleven states, both Kentucky and Missouri sent representatives to the Confederate Congress, while simultaneously sending representatives to the United States Congress.