When Burnside took over command of the army from McClellan in the fall, he formed the army into four Grand Divisions. The Right Grand Division was commanded by Edwin Sumner and comprised the II and XI Corps, the Center Grand Division, commanded by Joe Hooker, comprised the V and III Corps, and the Left Grand Division, commanded by William Franklin, comprised the VI and I Corps. In addition, the Reserve Grand Division, commanded by Franz Sigel, comprised the XI and XII Corps.