The stalemate was broken by the arrival of the Michigan Brigade under Brig. Gen. George A. Custer. He deployed his 5th Michigan on the right of Bottoms Bridge Road, the 1st and 7th Michigan on the left, and the 6th Michigan in reserve. Their attack flanked the Confederates on both ends of the line. As Butler's men fled to the rear, his reserve regiment, the 7th South Carolina, counterattacked in an attempt to maintain the line. The superior Union numbers and firepower—the Michiganders were armed with Spencer repeating rifles and Torbert had deployed horse artillery, a weapon that Butler did not have available—carried the day. Although almost all the fighting in the battle was dismounted, Col. Frank A. Haskell and Maj. Edward M. Boykin (cousin of the famous Confederate diarist, Mary Chesnut) led the 7th on horseback, and both were severely wounded during the charge. The 20th Georgia Battalion arrived at the end of the battle and were almost swamped by their colleagues racing away on horseback. The Union troopers pursued the retreating Confederates with enthusiasm. Butler eventually rallied his men at Old Cold Harbor and Torbert's men bivouacked about 1.5 miles northeast of the intersection.