The regiment served as part of the Horn Brigade for most of its service.

The 49th Ohio Infantry Regiment was organized at Camp Noble in Tiffin, Ohio, August and September 1861 and mustered in for three years service under the command of Colonel William H. Gibson.

The 49th Ohio Infantry has the distinction of being the first Union regiment to enter Kentucky after Confederate forces violated the state's neutrality.

The regiment was attached to Johnson's Brigade, McCook's Command, at Nolin, Ky., to November 1861.

6th Brigade, 2nd Division, I Corps, Army of the Ohio, to November 1862.

1st Brigade, 2nd Division, Right Wing, XIV Corps, Army of the Cumberland, to January 1863.

1st Brigade, 2nd Division, XX Corps, Army of the Cumberland, to October 1863.

The 49th Ohio Infantry mustered out of service at Victoria, Texas on November 30, 1865.

Advance to Bowling Green, Ky., and Nashville, Tenn., February 14 – March 3.

Advance on and siege of Corinth, Miss., April 29 – May 30 March to Battle Creek, Ala., June 10 – July 18, and duty there until August 20.

March to Louisville, Ky., in pursuit of Bragg August 20 – September 26.

March to Nashville, Tenn., October 16 – November 7, and duty there until December 26.

Passage of the Cumberland Mountains and Tennessee River and Chickamauga Campaign August 16 – September 22.

Operations on line of Pumpkin Vine Creek and battles about Dallas, New Hope Church and Allatoona Hills May 25 – June 5.

Duty at Green Lake, San Antonio and Victoria until November.