During the artillery barrage that preceded the infantry assault, Longstreet began to agonize over the assault. He attempted to pass the responsibility for launching Pickett's division to his artillery chief, Col. Edward Porter Alexander. When the time came to actually order Pickett forward, Longstreet could only nod in assent, unable to verbalize the order. The assault, known as Pickett's Charge, suffered the heavy casualties that Longstreet anticipated. It was the decisive point in the Confederate loss at Gettysburg and Lee ordered a retreat back to Virginia the following day.