The seven-company 15th Louisiana Cavalry Battalion was formed in January 1863 by Isaac F. Harrison.

At Choctaw Bayou and other places, the battalion tried but failed to stop the army of Major General Ulysses S. Grant from moving down the Mississippi River in April 1863.

Elements of the battalion fought at Milliken's Bend and raided Union camps in June 1863.

[1] The unit served for the entire war west of the Mississippi River in the Trans-Mississippi Department.

The regiment resisted minor Union raids in the Alexandria and Monroe areas before formally surrendering on 26 May 1865.