The first shots of the Battle of Chancellorsville were fired at 11:20 a.m. as the armies collided. McLaws's initial attack pushed back Sykes's division. The Union general organized a counterattack that recovered the lost ground. Anderson then sent a brigade under Brig. Gen. Ambrose Wright up an unfinished railroad south of the Plank Road, around the right flank of Slocum's corps. This would normally be a serious problem, but Howard's XI Corps was advancing from the rear and could deal with Wright.^[3]

Sykes's division had proceeded farther forward than Slocum on his right, leaving him in an exposed position. This forced him to conduct an orderly withdrawal at 2 p.m. to take up a position behind Hancock's division of the II Corps, which was ordered by Hooker to advance and help repulse the Confederate attack. Meade's other two divisions made good progress on the River Road and were approaching their objective, Banks's Ford.^[3]