There were three formations known as the Army of Mississippi in the Confederate States Army during the American Civil War. This name is contrasted against Army of the Mississippi, which was a Union army named for the Mississippi River, not the state of Mississippi.
Army of Mississippi (March 1862) This army, at times known by the name Army of the West was one of the most important in the western theater, fighting at Shiloh, Corinth, and Perryville. It was organized on March 5, 1862, and portions of the Army of Pensacola were added on March 13. It was consolidated with the Army of Central Kentucky and the Army of Louisiana on March 29. On November 20, 1862, it was renamed the Army of Tennessee.
Command history Commander From To Major Battles and Campaigns Gen. P.G.T. Beauregard March 5, 1862(assumed March 17, 1862) March 29, 1862 Gen. Albert Sidney Johnston (KIA) March 29, 1862 April 6, 1862 Shiloh Gen. P.G.T. Beauregard April 6, 1862 May 6, 1862 Gen. Braxton Bragg May 6, 1862(assumed May 7, 1862) July 5, 1862 Corinth Maj. Gen. William J. Hardee (temp) July 5, 1862 August 15, 1862 Gen. Braxton Bragg August 15, 1862 September 28, 1862 Lt. Gen. Leonidas Polk (temp) September 28, 1862 November 7, 1862 Perryville Gen. Braxton Bragg November 7, 1862 November 20, 1862
Army of Mississippi (December 1862) The second army was referred to as the Army of Vicksburg. It was organized December 7, 1862, by troops in the Department of Mississippi and East Louisiana, including the short-lived Army of West Tennessee. Its sole function was to defend Vicksburg, Mississippi, on the Mississippi River. It ceased to exist when southern General John C. Pemberton surrendered it after a long offensive campaign and siege to Major General Ulysses S. Grant on July 4, 1863, opening up the "Father of Waters" to Union control and splitting the Confederacy in two.
Command history Commander From To Major Battles and Campaigns Lt. Gen. John C. Pemberton December 7, 1862 December 9, 1862 Maj. Gen. Earl Van Dorn (temp) December 9, 1862 December 17, 1862 Lt. Gen. John C. Pemberton December 17, 1862 July 4, 1863 Vicksburg Campaign
Army of Mississippi (1863–64) The third army was retitled III Corps, Army of Tennessee, around May 4, 1864, but it continued to use the former name.
Command history Commander From To Major Battles and Campaigns Lt. Gen. William J. Hardee July 30, 1863 October 23, 1863 Lt. Gen. Leonidas Polk October 23, 1863 June 14, 1864 Atlanta campaign Maj. Gen. William W. Loring June 14, 1864 July 4, 1864
References Eicher, John H., & Eicher, David J., Civil War High Commands, Stanford University Press, 2001, .