3rd Brigade, 1st Division, Left Wing, XIV Corps, Army of the Cumberland, to January 1863.

1st Separate Brigade, Chattanooga, Tennessee, Department of the Cumberland, to September 1864.

The 51st Indiana Infantry mustered out of service at San Antonio, Texas, on December 13, 1865.

December 14: Moved to Louisville, KY until February 1862: to Bardstown, KY (and duty there) February 7-March 13, 1862: March to Nashville, TN March 29-April 6: March to Savannah, TN April 6–7: Battle of Shiloh April 29-May 30: Advance on and siege of Corinth, MS May 31-June 12: Pursuit to Booneville June to August: Buell's Campaign in northern Alabama and middle Tennessee August 21-September 26: Guarding Memphis & Charleston Railroad.

October 22-November 7: March to Nashville, TN until December 26: Duty in Nashville, TN December 25: Prim's Blacksmith Shop, Edmonson Pike December 26–30: Advance on Murfreesboro December 30–31, 1862 and January 1–3, 1863: Battle of Stones River until April: Duty at Murfreesboro January 13–15: Reconnaissance to Nolensville and Versailles April 26-May 3: Streight's Raid to Rome, GA April 30: Dug Gap, Sand Mountain, Crooked Creek and Hog Mountain May 1: East Branch Black Warrior Creek May 2: Blount's Farm May 3: near Centre Galesville (Cedar Bluff) (where the regiment was captured) November 1863: Exchanged December 1863: Reorganized at Indianapolis, IN, and rejoined the army at Nashville, TN June 23-July 7: (A detachment on Tullahoma Campaign) until April 1864: Assigned to duty as guard on Railroad, between Nashville and Chattanooga until September 1864: Duty at Chattanooga until October: Duty at Atlanta August 14–15: Action at Dalton, GA October 3–26: Pursuit of Hood into Alabama November–December: Nashville Campaign November 24–27: Columbia, Duck River November 30: Battle of Franklin December 15–16: Battle of Nashville December 17–28: Pursuit of Hood to the Tennessee River December 21: Columbia December 22: Duck River December 14, 1864: Non-veterans mustered out until March 1865: Moved to Huntsville, AL (and duty there) March 15-April 22: Operations in eastern TN until June: At Nashville June 16: Ordered to New Orleans July: To TX until December: Duty at Green Lake and San Antonio The regiment lost a total of 264 men during service; 1 officer and 55 enlisted men killed or mortally wounded, 6 officers and 202 enlisted men died of disease.