The 18th Kentucky Infantry Regiment was organized at large and mustered in for a three-year enlistment on February 8, 1862, under the command of Colonel William A. Warner.
The regiment served unattached, Army of the Ohio, to August 1862.
1st Brigade, 2nd Division, Army of Kentucky, Department of the Ohio, to October 1862.
Unattached, Army of Kentucky, Department of the Ohio, to December 1862.
1st Brigade, 2nd Division, Army of Kentucky, to February 1863.
Crook's Brigade, Baird's Division, Army of Kentucky, Department of the Cumberland, to June 1863.
3rd Brigade, 4th Division, XIV Corps, Army of the Cumberland, to October 1863.
Moved to Lexington, Ky., December 5; thence to Louisville, Ky., January 27, 1863, and to Nashville, Tenn., February 2.
Passage of Cumberland Mountains and Tennessee River and Chickamauga Campaign August 16-September 22.
Brown's Ferry October 27, Chattanooga-Ringgold Campaign November 23–27.
Assigned May 10 to post duty at Ringgold, Ga. Relieved September 25 and moved to Atlanta, Ga. Operations against Hood in northern Georgia and northern Alabama October 3–26.