While Hancock was in the Po sector, Warren requested permission from Meade to attack Laurel Hill at 4 p.m., uncoordinated with the rest of Grant's attack. Again the Laurel Hill line repulsed the Union troops with heavy losses. Grant was forced to postpone his 5 p.m. coordinated assault until Warren could get his troops reformed. Not informed of the delay, Brig. Gen. Gershom Mott of the II Corps moved his division forward at 5 p.m. toward the tip of the Mule Shoe. When his men reached the open field, Confederate artillery ripped them to shreds, and they retreated. At around 6 p.m., Col. Emory Upton led a group of 12 hand-picked regiments, about 5,000 men in four battle lines, against an identified weak point on the west side of the Mule Shoe. The plan was for Upton's men to rush across the open field without pausing to fire and reload, reaching the earthworks before the Confederates could fire more than a couple of shots. The plan worked well initially, but Generals Lee and Ewell were quick to organize a vigorous counterattack with brigades from all sectors of the Mule Shoe. No Union supporting units arrived. Upton's men were driven out of the Confederate works, and he reluctantly ordered them to retreat.