On Steptember 13 the regiment was transferred to the 4th Brigade, 2nd Division in the III Corps of the Army of the Ohio under Maj. Gen. Don Carlos Buell.

During the battle, the regiment, as part of the Union left flank, was attacked by a Confederate division was forced to fall back.

When additional Confederate divisions joined the fray, the Union line made a stubborn stand, counterattacked, but finally fell back with some units routed.

The regiment, as part right flank of the army, was overrun in a surprise attack at dawn on December 31, with the 2nd division overall suffering over 50% casualties.

[4] As part of a column under the command of Maj. Gen. William Tecumseh Sherman, the IV Corps participated in the Relief of Knoxville from November 28 – December 7, 1863.

The IV Corps remained in Knoxville to reinforce Maj. Gen. Ambrose Burnside before rejoining the Army of the Cumberland in spring 1864 for the Atlanta Campaign under the command of Maj. Gen. Oliver O.

[10] Following the Franklin-Nashville Campaign, the 79th Illinois was stationed at Decatur, Alabama from January 6 - March 30, 1865, followed by Nashville, Tennessee from April 22 - June 12.