Second Battle of Bull Run - Opposing forces. 1  Maj. Gen. John Pope, Army of Virginia (Commanding), USA. 2  Maj. Gen. Franz Sigel (I Corps, Army of Virginia), USA. 3  Maj. Gen. Nathaniel P. Banks (II Corps, Army of Virginia), USA. 4  Maj. Gen. Irvin McDowell (III Corps, Army of Virginia), USA.