Gregg lost 829 (estimated) killed and wounded. The severest losses in the brigade fell on the Rifles, the Fourteenth and the Twelfth. The Rifles lost 319, the Fourteenth, 291, and the Twelfth, 155. At one time every one of the color-guards of the First volunteers was shot down around Colonel Hamilton, who took the colors. The color-bearer, Sergeant Taylor, fell with the colors in his grasp, as he was planting them forward of the line, and Corporal Hayne, seeing Colonel Hamilton take the flag, seized it, and gallantly going forward, fell mortally wounded. Private Spillman, of Company K, then took the flag and carried it to the final charge in triumph to victory. He was promoted color-bearer on the field for gallant conduct. Among the lamented dead of the First was the gallant and accomplished Lieut.-Col. A. M. Smith, who left a sick bed to take his place in his country's service. In the Twelfth, Colonel Barnes was wounded, but did not leave the field. Lieut. J. W. Delaney, commanding Company B, was killed in the first assault; Captain Vallandingham lost a leg, and Captains Miller, McMeekin and Bookter were wounded. In the Thirteenth, which was mainly in support, the loss was not so heavy, 8 killed and 40 wounded. In the Fourteenth, Colonel McGowan and Maj. W. J. Carter were wounded, as were also Captains Brown, Taggart and Edward Croft, and Lieutenants Brunson, O. W. Allen, Stevens, McCarley, Dorrah and Carter; and the gallant Lieut. O. C. Plunkett, Company H, was killed on the field. The First Rifles (known as Orr's Rifles) suffered terribly. Its gallant adjutant, J. B. Sloan, Captains Hawthorne and Hennegan, Lieutenants Brown and McFall, and Sergeant-Major McGee died heroically leading in Marshall's charge. In Gregg's battle, a section of Capt. D. G. Mcintosh's battery was called into action late in the afternoon, too late to take an active part in the battle, as the enemy's artillery in front had been silenced, or had retired. He lost 1 man killed and 2 wounded, and 5 horses killed.
The other South Carolina troops at the battle of Gaines' Mill were with Hood and Longstreet. The brigades of Hood and Law composed Whiting's gallant division, which had marched from Ashland as the advance of Jackson's corps. They went into battle in the late afternoon, after A. P. Hill had been fighting for two hours.[B] With Hood was the Hampton legion infantry, under Lieut.-Col. M. W. Gary, and with Longstreet was R. H. Anderson's South Carolina brigade. These troops had the honor of taking part in Longstreet's and Whiting's final charge along the front and flank of the Federal left, and were among the first to gain the coveted crest and pierce and turn his flank, capture his artillery and decide the day.