The Confederate States Army (CSA) was the military ground force of the Confederate States (C.S.), also known as the "Confederacy", while the Confederacy existed during the American Civil War. On February 28, 1861, the Provisional Confederate Congress established a provisional volunteer army and gave control over military operations and authority for mustering state forces and volunteers to the Confederate president, Jefferson Davis, a graduate of the U.S. Military Academy and colonel of a volunteer regiment during the Mexican War. In March 1861, the Provisional Confederate Congress established a more permanent Confederate States Army.