The 126th Ohio Infantry was organized at Camp Steubenville in Steubenville, Ohio,[1] and mustered in for three years service on September 4, 1862,[2] under the command of Colonel Benjamin Franklin Smith.

[3] The regiment was attached to Railroad Division, Western Virginia, to January 1863.

Martinsburg, Virginia, VIII Corps, Middle Department, to March 1863.

3rd Brigade, French's Command, VIII Corps, to July 1863.

3rd Brigade, 3rd Division, III Corps, Army of the Potomac, to March 1864.

2nd Brigade, 3rd Division, VI Corps, Army of the Potomac and Army of the Shenandoah, Middle Military Division, to June 1865.

The 126th Ohio Infantry mustered out of service at Washington, D.C., on June 25, 1865.

Moved to Cumberland, Maryland., October 17, 1862, and to North Mountain December 12.

Guard duty on Baltimore & Ohio Railroad from North Mountain to Martinsburg December 12–20, and duty at Martinsburg until June 14, 1863.

Duty in New York City during draft disturbances August 18-September 5.