march up the river, crossed the river at Boteler's Ford, a short distance below Shepherdstown, and arrived on the field of Sharpsburg in the afternoon, about 2 miles from the Potomac, reaching the actual presence of the enemy at 3.40 p.m., which was not a moment too soon for the fortunes of the day. The general line of our army seemed to be in front of the town of Sharpsburg, facing east, with its right flank stretching toward the Potomac. The enemy were in front along the line of the Antietam River. We came upon the field on the extreme right of our line, perhaps 2 miles from the Potomac. It was seen at once that a large force of the enemy (said to be Burnside's division) were in the act of sweeping down the Antietam and around our right, with the object, manifestly, of cutting off our army from the Potomac. The Light Division came from the proper direction and at the right moment to meet this column and drive it back across the Antietam. Gregg's brigade was placed in position on the right. The Fourteenth South Carolina Volunteers (Lieutenant-Colonel Simpson) being the leading regiment, was not actively engaged. The First (Colonel Hamilton), Twelfth (Colonel Barnes), and Thirteenth South Carolina Volunteers (Colonel Edwards) formed in line of battle, and were directed to enter the field to the left of the Fourteenth and drive back the enemy. This line advanced to the top of a hill in a corn-field, and there engaged the enemy, who appeared advancing in force upon the opposite hill, and held a fence in the ravine between the hills. They checked at once the advance of the enemy. Colonel Edwards, on the left, took up a strong position behind a stone fence and held it. Colonel Barnes advanced down the hill, and with a charge gallantly drove the enemy from the fence in front. He was, however, in a few moments flanked by a large body on the right, and had to retire his regiment a short distance up the hill, the enemy immediately reoccupying the fence. Colonel Barnes soon returned to the attack, and upon the same ground charged with his fine regiment three times, and the last time drove them from the fence and up the hill beyond, with great slaughter.
In the mean time Colonel Hamilton, feeling a heavy pressure upon his right, oblique his regiment in that direction and gallantly drove them, clearing the front and at the same time covering the right of Colonel Barnes. A heavy body now appeared on the right of Colonel Hamilton, and Captain Perrin, commanding Orr's Rifles, was sent out to sweep the field in that direction. He led his regiment up a hill, discovered the enemy in the hollow beyond, dispersed them at once, and held the position, which was somewhat in advance of the general line. Thus, the columns which were enveloping the right of our army were driven back at all points, and, at the last moment, Sharpsburg made a victory for the Confederate arms.
The brigade held its position on the field all night, the next day, and until 3 o'clock in the morning of Friday, the 19th, when they joined the division and moved toward Boteler's Ford, on the Potomac, which was crossed without losing a man. In the critical operation of crossing the river in the face of so large a force, the Light Division (General A. P. Hill) was the rear guard, and Gregg's brigade was in rear of the division. Two companies of the Fourteenth South Carolina Volunteers, under the command of Captain Brown, were thrown out by Lieutenant-Colonel [W. D.] Simpson as skirmishers, in a corn-field about a mile from the river, thus covering the passage of the army.