Key Union Commanders
The Department of the Mississippi, commanded by Maj.
Gen. Henry Halleck, was divided into three wings.
Each wing corresponded to one of the three armies under his command.
It totaled 120,172 men “present for duty”.

The Army of the Mississippi, designated the “Left Wing”, commanded by Maj.
Gen. John Pope, totaled 21,510 men “present for duty”.

The Army of the Ohio, designated the “Center Wing”, commanded by Maj.
Gen. Don Carlos Buell, totaled 48,108 men “present for duty”.

The Army of the Tennessee, designated the “Right Wing”, commanded by Maj.
Gen. George H. Thomas, totaled 50,554 men “present for duty”.
Key Union Commanders
The Department of the Mississippi, commanded by Maj. Gen. Henry Halleck, was divided into three wings. Each wing corresponded to one of the three armies under his command. It totaled 120,172 men “present for duty”.
The Army of the Mississippi, designated the “Left Wing”, commanded by Maj. Gen. John Pope, totaled 21,510 men “present for duty”.
The Army of the Ohio, designated the “Center Wing”, commanded by Maj. Gen. Don Carlos Buell, totaled 48,108 men “present for duty”.
The Army of the Tennessee, designated the “Right Wing”, commanded by Maj. Gen. George H. Thomas, totaled 50,554 men “present for duty”.
Siege of Corinth