The 116th Illinois Infantry was organized in Decatur, Illinois, and mustered in for three years service on September 30, 1862, under the command of Colonel Nathan W. Tupper.
The regiment was attached to 4th Brigade, 5th Division, District of Memphis, XIII Corps, Department of the Tennessee, November 1862.
2nd Brigade, 2nd Division, District of Memphis, XIII Corps, to December 1862.
1st Brigade, 2nd Division, Sherman's Yazoo Pass Expedition, to January 1863.
1st Brigade, 2nd Division, XV Corps, Army of the Tennessee, to June 1865.
The 116th Illinois Infantry mustered out of service on June 7, 1865.
Assault on and capture of Fort Hindman, Arkansas Post, January 10–11.
Moved to Young's Point, Louisiana, January 17–22, and duty there until March.
Expedition to Rolling Fork, Mississippi, via Muddy, Steele's and Black Bayous, and Deer Creek, March 14–27.
Movement to Jackson, Mississippi, via Grand Gulf, May 2–14.
Moved to Memphis, Tennessee; then marched to Chattanooga September 26-November 20.
Operations on Memphis & Charleston Railroad in Alabama October 20–29.
Operations on line of Pumpkin Vine Creek and battles about Dallas, New Hope Church, and Allatoona Hills May 25-June 5.
Operations about Marietta and against Kennesaw Mountain June 10-July 2.
Ball's Ferry and Georgia Central Railroad Bridge, Oconee River, November 23–25.