a massive bayonet charge to overwhelm the defenders, but as he surveyed the front, he quickly realized that French's and Hancock's divisions were in no shape to move forward again. He next planned for his final division, commanded by Maj. Gen. Oliver O. Howard , to swing to the right and attempt to envelop the Confederate left, but upon receiving urgent requests for help from French and Hancock, he sent Howard's men over and around the fallen troops instead. The brigade of Col. Joshua Owen went in first, reinforced by Col. Norman J. Hall 's brigade, and then two regiments of Brig. Gen. Alfred Sully 's brigade. The other corps in Sumner's grand division was the IX Corps, and he sent in one of its divisions under Brig. Gen. Samuel Sturgis . After two hours of desperate fighting, four Union divisions had failed in the mission Burnside had originally assigned to one. Casualties were heavy: II Corps losses for the afternoon were 4,114, Sturgis's division 1,011. [ 32 ] While the Union Army paused, Longstreet reinforced his line so that there were four ranks of infantrymen behind the stone wall. Brig. Gen. Thomas R. R. Cobb of Georgia, who had commanded the key sector of the line, was mortally wounded by an exploding artillery shell and was replaced by Brig. Gen. Joseph B. Kershaw . General Lee expressed concerns to Longstreet about the massing troops breaking his line, but Longstreet assured his commander, "General, if you put every man on