In its various forms, the Third Corps served under William J. Hardee, Edmund Kirby Smith, Simon Bolivar Buckner, Leonidas Polk, and Alexander P. Stewart.

Having previously served in Kentucky and Tennessee, Hardee's division was marched to Corinth in the personal accompaniment of General Albert Sidney Johnston as part of a strategic Confederate concentration leading up to the Battle of Shiloh.

This "corps" remained a division in structure, consisting of three brigades under Brigadier Generals Thomas Hindman, Patrick Cleburne, and S.A.M.

Additionally, an artillery battalion of three Arkansas batteries under Major Francis Shoup was also attached to the corps.

Though they had departed in the morning, it was late into the afternoon by the time the last of Hardee's corps had left Corinth.

[3] Poor staff work combined with muddy roads and conditions delayed the march, and thus the attack, well past the April 4th target date.

[4] Largely because of its position at the head of the line of march and camp, Hardee's corps found itself at the spearhead of the attack on the morning of April 6th.

Thus it was Hardee's corps that became the first Confederates engaged in the Battle of Shiloh when a Federal patrol under Major James Powell from Colonel Everett Peabody's brigade stumbled into a cavalry outposts and pickets from Major Aaron Hardcastle's 3rd Mississippi Battalion of Wood's brigade.

The brigades which made up the corps later constituted a division under Simon Buckner, and then more famously, Patrick Cleburne.

This proved to be a key factor in the battle and many say if Braxton Bragg had Smith and his four divisions, he may have won decisively, not only tactically.

McCown was assigned to Hardee's corps, and thus his division became a permanent part of the Army of Tennessee.

Loring and his division broke out and later on served in two other Third Corps but the rest of the 'Corps', usually known as the Army of Mississippi, surrendered on July 4.

Johnson's division was detached to operate with Longstreet's corps at Chickamauga however, and was broken up shortly after the battle.

It also contained a division of 7,500 under Samuel French from Mississippi and finally 6,000 men from Mobile under general Cantey (later under Walthall).

Stewart's corps fought heavily at Peachtree Creek, where it broke through George Henry Thomas's lines.

It fought heavily at Allatoona Pass, and assaulted the Union left at the disastrous Battle of Franklin.