Chickamauga Union order of battle

The following Union Army units and commanders fought in the Battle of Chickamauga of the American Civil War. The Confederate order of battle is listed separately. Order of battle compiled from the army organization during the campaign.
Army of the Cumberland.
MG William Rosecrans, Commanding
General Staff
Chief of Staff: BG James A. Garfield
General Headquarters
Pioneer Brigade
BG James St. Clair Morton, Chief Engineer (w)
XIV Corps.
MG George Henry Thomas
Headquarters
Provost guard:
Escort:
XX Corps.
MG Alexander McDowell McCook
Headquarters
Provost guard:<br>
81st Indiana Infantry, Company H: Cpt William J. Richards
Escort:<br>
2nd Kentucky Cavalry, Company I: Lt George W. L. Batman
XXI Corps.
MG Thomas Leonidas Crittenden
Headquarters
Escort:<br>
15th Illinois Cavalry, Company K: Cpt Samuel B. Sherer
Reserve Corps.
MG Gordon Granger
Cavalry Corps.
BG Robert B. Mitchell