- March 5, 1862
- November 20, 1862
- Prior to Tennessee’s secession from the Union on June 8, 1861, the state legislature authorized Governor Isham Harris to enter into a military league with the Confederate States of America.
- On July 13, 1861, Governor Isham Harris authorized the Tennessee Provisional Army to serve under Confederate General Leonidas Polk, even though the state’s forces would not be folded into the Provisional Confederate Army until July 31.
- On September 10, 1861, the Confederate War Department issued Special Orders, No. 149, appointing General Albert Sidney Johnston to command of the Western Military Department, which encompassed most of the Confederacy west of the Appalachian Mountains and east of the Mississippi River.
- On March 5, 1862, General P.G.T. Beauregard issued a message announcing that he was assuming command of the force that he designated as “the Army of the Mississippi.”
- On March 29, Confederate General Albert Sidney Johnston issued General Orders, No. 1-8 (Headquarters of Forces at Corinth, Mississippi) announcing the consolidation of the troops in the Western Military Department as the Army of the Mississippi.
- The Army of the Mississippi was the primary Confederate force at the Battle of Shiloh (April 6–7, 1862).
- General Albert Sidney Johnston, commander of the Army of the Mississippi, was mortally wounded during the Battle of Shiloh on April 6, 1862.
- General P.G.T. Beauregard assumed command of the Army of the Mississippi during the Battle of Shiloh, after General Albert Sidney Johnston, was mortally wounded on April 6, 1862.
- After the Confederate defeat at the Battle of Shiloh, the Army of the Mississippi retreated to Corinth, Mississippi.
- On May 6, 1862, General P.G.T. Beauregard issued General Orders, No. 37, Headquarters of the Forces, placing General Braxton Bragg in command of the Army of the Mississippi.
- General P.G.T. Beauregard saved the Army of the Mississippi with a brilliantly executed evacuation of Corinth, Mississippi on May 29, 1862.
- On June 20, 1862, Confederate President Jefferson Davis appointed General Braxton Bragg as commander of the Western Department.
- On July 5, 1862, General Braxton Bragg issued General Orders, No. 22, temporarily handing off command of the Army of the Mississippi to Major General William J. Hardee.
- On August 15, 1862, General Braxton Bragg issued General Orders, No. 116 (Department No. 2) resuming his command of the Army of the Mississippi.
- On September 17, the Army of the Mississippi captured an important rail station at Munfordville, Kentucky, along with 4,000 Union soldiers, at the Battle of Munfordville (September 14-17, 1862).
- On October 8, 1862, the Army of the Mississippi won a tactical victory over Major General Don Carlos Buell’s Army of the Ohio at the Battle of Perryville.
- Lieutenant General Leonidas Polk commanded the Army of the Mississippi from September 28, through November 7, 1862.
- On November 20, 1862, General Braxton Bragg issued General Orders, No. 151, reorganizing his forces and designating his newly-structured command as the Army of Tennessee, thus bringing an end to the Army of the Mississippi.