The 12th Indiana Infantry was organized at Indianapolis, Indiana May 27 through August 27, 1862, and mustered in on August 17, 1862, for three year's service under the command of Colonel William H. Link.
The regiment was attached to Cruft's Brigade, Army of Kentucky, August 30.
Attached to 2nd Brigade, District of Memphis, Tennessee, XIII Corps, to December 1862.
1st Brigade, 1st Division, District of Memphis, XIII Corps, December 1862.
1st Brigade, 1st Division, XVII Corps, Army of the Tennessee, to January 1863.