The 110th Illinois Infantry was organized at Anna, Illinois, and mustered in for three years service on September 11, 1862, under the command of Colonel Thomas S. Casey.
The regiment was recruited in Franklin, Hamilton, Jefferson, Perry, Washington, Wayne, and Williamson counties.
Following its defense of the "Round Forest" (or "Hell's Half-Acre") with Hazen's Brigade in the Battle of Stones River, the regiment was consolidated into a battalion of four companies on orders dated May 7, 1863.
[1] The regiment was attached to 19th Brigade, 4th Division, II Corps, Army of the Ohio, to November 1862.
2nd Brigade, 2nd Division, Left Wing, XIV Corps, Army of the Cumberland, to January 1863.
2nd Brigade, 2nd Division, XXI Corps, Army of the Cumberland, to May 1863.
3rd Brigade, 2nd Division, XIV Corps, to June 1865.
Recruits to the regiment were transferred to the 60th Illinois Infantry.
Wild Cat Mountain, near Crab Orchard and Big Rockcastle River October 15–16.
Battle of Stones River December 30–31, 1862 and January 1–3, 1863.
Passage of the Cumberland Mountains and Tennessee River and Chickamauga Campaign August 16-September 22.
Tunnel Hill, Buzzard's Roost Gap, and Rocky Faced Ridge February 23–25.
Averysboro, Taylor's Hole Creek, North Carolina, March 16.
March to Washington, D.C., via Richmond, Virginia, April 29-May 19.