concert with his assault on the center. However, the fighting on Culp's Hill resumed early in the morning with a Union counterattack, hours before Longstreet could begin his attack on the center. The Union troops on fortified Culp's Hill had been reinforced and the Confederates made no progress after multiple, futile assaults that lasted until noon. The infantry assault on Cemetery Ridge known as Pickett's Charge was preceded by a massive artillery bombardment at 1 p.m. that was meant to soften up the Union defense and silence its artillery, but it was largely ineffective. Approximately 12,500 men in nine infantry brigades advanced over open fields for under heavy Union artillery and rifle fire. Although some Confederates were able to breach the low stone wall that shielded many of the Union defenders, they could not maintain their hold and were repulsed with over 50% casualties. During and after Pickett's Charge on the third day, two significant cavalry battles also occurred: one approximately to the east, in the area known today as East Cavalry Field, the other southwest of the [Big] Round Top mountain (sometimes called South Cavalry Field). The East Cavalry Field fighting was an attempt by Maj. Gen. J.E.B. Stuart's Confederate cavalry to get into the Federal rear and exploit any success that Pickett's Charge may have generated. Union cavalry under Brig. Gens. David McM. Gregg and George Armstrong Custer repulsed the Confederate advances. In South Cavalry Field, after Pickett's Charge had been defeated, reckless cavalry charges against the right flank of the Confederate Army, ordered by Brig. Gen. Judson Kilpatrick, were easily repulsed. The three-day battle in and around Gettysburg resulted in the largest number of casualties in the American Civil War—between 46,000 and 51,000. In conjunction with the Union victory at Vicksburg on July 4, Gettysburg is frequently cited as the war's turning point. Lee's retreat to Virginia Lee managed to escape back to Virginia after a harrowing forced march in the face of flooded rivers. Meade took the blame for the failure to capture Lee's highly vulnerable and outnumbered army. Following Pickett's Charge, the Confederates returned to their positions on Seminary Ridge and prepared fortifications to receive a counterattack. When the Union attack had not occurred by the evening of July 4, Lee realized that he could accomplish nothing more in his campaign and that he had to return his battered army to Virginia. Lee started his