 Despite an initial defeat due largely to faulty intelligence, through swift and careful maneuvers Jackson was able to defeat three separate Union armies and prevent any of them from reinforcing General George B. McClellan's Army of the Potomac in its campaign against Richmond.Jackson then quickly moved his three divisions to reinforce General Lee's Army of Northern Virginia in defense of Richmond.He performed poorly in the Seven Days Battles against George B. McClellan's Army of the Potomac, as he was frequently late arriving on the field.