Lee had not intended to fight before his army was fully concentrated, but chance and questionable decisions by A.P. Hill brought on the battle, which- on the first day- was an impressive Confederate victory.
Det havde ikke været Lee’s mening at kæmpe, før hans hær var samlet, men tilfældigheder og tvivlsomme beslutninger af A.P. Hill satte slaget i gang, og den første dag var en imponerende sejr for Sydstaterne.