The range known as the South Mountain, which is a continuation of the Blue Ridge north of the Potomac, is about a thousand feet high. The two principal gaps are Turner's and Crampton's, each about four hundred feet high, with the hills towering six hundred feet above it. When McClellan learned the plans of the Confederate commander, he set his army in motion to thwart them. He ordered Franklin's corps to pass through Crampton's Gap and press on to relieve Harper's Ferry; the corps of Reno and Hooker, under command of Burnside, he moved to Turner's Gap. The movement was quick for McClellan, but not quite quick enough for the emergency. He might have passed through the Gaps on the 13th with little or no opposition, and would then have had his whole army between Lee's divided forces, and could hardly have failed to defeat them disastrously and perhaps conclusively. But he did not arrive at the passes till the morning of the 14th; and by that time Lee had learned of his movement and recalled Hill and Longstreet, from Boonsborough and beyond, to defend Turner's Gap, while he ordered McLaws to look out for Crampton's. Turner's Gap was flanked by two old roads that crossed the mountain a mile north and south of it; and using these, and scrambling up from rock to rock, the National troops worked their way slowly to the crests, opposed at every step by the Confederate riflemen behind the trees and ledges. Reno assaulted the southern crest, and Hooker the northern, while Gibbon's brigade gradually pushed along up the turnpike into the Gap itself. Reno was opposed by the Confederate brigade of Garland, and both these commanders were killed. There was stubborn and bloody fighting all day, with the Union forces slowly but constantly gaining ground, and at dark the field was won. The Confederates withdrew during the night, and in the morning the victorious columns passed through to the western side of the mountain. This battle cost McClellan fifteen hundred men, killed or wounded. Among the wounded was the lieutenant-colonel in command of the Twenty-third Ohio regiment--Rutherford B. Hayes, afterward President--who was struck in the arm by a rifle-ball. The Confederate loss in killed and wounded was about fifteen hundred, and in addition fifteen hundred were made prisoners. The fight at Crampton's Gap--to defend which McLaws had sent back a part of his force from Harper's Ferry--was quite similar to that at Turner's, and had a similar result. Franklin reached the crests after a fight of three hours, losing five hundred and thirty-two men, inflicting an equal loss upon the enemy, and capturing four hundred prisoners, one gun, and three battle-flags. These two actions (fought September 14, 1862) {177} are generally designated as the battle of South Mountain, but are sometimes called the battle of Boonsborough. In that the enemy was driven away, the ground held, and the passes used, it was a victory, and a brilliant one, for McClellan.