The 65th Ohio Infantry Regiment was organized at Camp Buckingham in Mansfield, Ohio,[1][2] beginning October 3, 1861, and mustered in for three years service on November 14, 1861, under the command of Colonel Charles Garrison Harker, who was 23 years old at the time.

[3] The regiment was recruited in Ashland, Columbiana, Cuyahoga, Erie, Guernsey, Hancock, Knox, and Stark counties.

The regiment was attached to 20th Brigade, Army of the Ohio, to January 1862.

20th Brigade, 6th Division, Army of the Ohio, to September 1862.

20th Brigade, 6th Division, II Corps, Army of the Ohio, to November 1862.

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

3rd Brigade, 1st Division, XXI Corps, Army of the Cumberland, to October 1863.

3rd Brigade, 2nd Division, IV Corps, Army of the Cumberland, to June 1865.

The 65th Ohio Infantry mustered out of service at San Antonio, Texas, on November 30, 1865, and was discharged January 2, 1866.

[1] Moved to Louisville, Ky., December 18; thence to Bardstown and to Hall's Gap, Ky., January 13, 1862.

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.

Ruff's Station, Smyrna Camp Ground, July 4.

Moved to New Orleans, La., June 16; thence to Texas and duty at San Antonio until December.