The 123rd Indiana Infantry was organized at Greensburg, Terre Haute, and Indianapolis, Indiana beginning December 25, 1863 and mustered in under the command of Colonel John Craven McQuiston.
The regiment was attached to 2nd Brigade, 1st Division, XXIII Corps, Army of the Ohio, to June 1864.
4th Brigade, 3rd Division, XXIII Corps, to August 1864.
3rd Brigade, 2nd Division, XXIII Corps, to December 1864.
2nd Brigade, 1st Division, XXIII Corps, Army of the Ohio, to February 1865, and Department of North Carolina to August 1865.
The 123rd Indiana Infantry mustered out of service August 25, 1865.
Operations on Pumpkin Vine Creek and battles about Dallas, New Hope Church, and Allatoona Hills May 25-June 5.
Movement to Washington, D.C.; then to Morehead City, North Carolina, January 15-February 24.
Duty at Charlotte and Raleigh, North Carolina, until August.