The Army of the Cumberland (Union) commanded by Maj. Gen. William S.
Rosecrans, consisted of the following:
14th Army Corps Maj. Gen. George H. Thomas
20th Army Corps Maj. Gen. Alexander McD. McCook
21st Army Corps Maj. Gen. Thomas L. Crittenden
Cavalry Corps Brig. Gen. Robert B. Mitchell
Reserve Corps Maj. Gen. Gordon Granger
Thomas had 4 divisions, commanded by Baird, Negley, Brannan and
Reynolds.
Baird had 3 brigades, commanded by Scribner, Starkweather and John
H. King.
Negley had 3 brigades, commanded by John Beatty, Stanley and
Sirwell.
Brannan had 3 brigades, commanded by Connell, Croxton and Van
Derveer.
Reynolds had 3 brigades, commanded by Wilder, Edward A. King and
Turchin.
McCook had 3 divisions, commanded by Jefferson C. Davis, Richard W.
Johnson and Sheridan.
Davis had 3 brigades, commanded by Post, Carlin and Heg.
Johnson had 3 brigades, commanded by Willich, Dodge and Baldwin.
Sheridan had 3 brigades, commanded by Lytle, Laiboldt and Bradley.
Crittenden had 3 divisions, commanded by Thomas J. Wood, Palmer and
Van Cleve.
Wood had 3 brigades, commanded by Geo. P. Buell, Wagner and Harker.
Palmer had 3 brigades, commanded by Cruft, Hazen and Gross.
Van Cleve had 3 brigades, commanded by Sam Beatty, Dick and Barnes.
Granger had 1 division, commanded by Steedman, consisting of 2
brigades, commanded by Whitaker and Mitchell. The 2nd
brigade of Morgan’s division commanded by Daniel McCook,
also participated in the battle.
Mitchell had 2 divisions, commanded by Edward M. McCook and Crook.
McCook had 3 brigades, commanded by Campbell, Ray and Watkins.
Crook had 2 brigades, commanded by Minty and Long.
Of these 38 brigades, 36 were engaged. Post’s brigade was guarding
supply trains. Wagner’s brigade was stationed at Chattanooga during the
battle. Wilder’s brigade was detached and serving as mounted infantry.
There were two regiments not engaged. The 9th Michigan Infantry and the
38th Ohio Infantry were guarding trains and performing Provost Duty. The
39th Indiana Infantry also served as mounted infantry (being detached).