The first attempt at a unified cavalry command occurred in late 1862/63, when William S. Rosecrans, commanding the Army of the Cumberland, organized all of his cavalry into a single division, acting as a separate command from the infantry, under the command of David S. Stanley. This new division fought respectably, if unremarkably, at Stones River. During the Tullahoma Campaign this cavalry division was expanded to corps size. Stanley commanded the corps with Robert B. Mitchell and John B. Turchin commanding the 1st and 2nd Divisions respectively. Mitchell commanded the corps at Chickamauga while Edward M. McCook and George Crook commanded the divisions.