side of the Shenandoah, so as to enfilade the enemy's intrenchments on Bolivar Heights, and take his nearest and most formidable works in reverse. General McLaws in the mean time made his preparations to prevent the force which had penetrated at Crampton's Gap from coming to the relief of the garrison. This pass had been defended by the brigade of General Cobb, supported by those of Semmes and Mahone; but unable to oppose successfully the superior numbers brought against them, they had been compelled to retire with loss. The enemy halted at the gap, and during the night General McLaws formed his command in line of battle across Pleasant Valley, about 1 1/2 miles below Crampton's [Gap], leaving one regiment of support the artillery on Maryland Heights, and two brigades on each of the roads from Harper's Ferry.

The attack on the garrison began at dawn. A rapid and vigorous fire was opened from the batteries of General Jackson and those on Maryland and Loudoun Heights. In about two hours the garrison, consisting of more than 11,000 men, surrendered. Seventy-three pieces of artillery, about 13,000 small-arms, and a large quantity of military stores, fell into our hands. Leaving General A. P. Hill to receive the surrender of the Federal troops and secure the captured property, General Jackson, with his two other divisions, set out at once for Sharpsburg, ordering Generals McLaws and Walker to follow without delay. Official information of the fall of Harper's Ferry and the approach of General Jackson was received soon after the commands of Longstreet and D. H. Hill reached Sharpsburg, on the morning of the 15th, and reanimated the courage of the troops. General Jackson arrived early on the 16th and General Walker came up in the afternoon. The presence of the enemy at Crampton's Gap embarrassed the movements of General McLaws. He retained the position taken during the night of the 14th to oppose an advance toward the potomac. Deeming the roads to Sharpsburg on the north side of the river impracticable, he resolved to cross at Harper's Ferry and march by way of Shepherdstown. Owing to the condition of his troops and other circumstances, his progress was slow, and he did not reach the battle-field at Sharpsburg until some time after the engagement of the 17th began. The commands of Longstreet and D. H. Hill, on their arrival at Sharpsburg, were placed in position along the range of hills between the town and the Antietam, nearly parallel to the course of that stream, Longstreet on the firth of the road to Boonsborough and Hill on the left. The advance of the enemy was delayed by the brave opposition he encountered from Fitzhugh Lee's cavalry, and he did not appear on the opposite side of the Antietam until about 2 p. m. During the afternoon the batteries on each side were slightly engaged.

On the 16th artillery fire became warmer, and continued through-out the day. The enemy crossed the Antietam beyond the reach of our batteries and menaced our left. In anticipation of this movement, Hood's two brigades had been transferred from the right and posted between D. H. Hill and the Hagerstown road. General Jackson was now directed to take position on Hood's left, and formed his line with his right resting upon the Hagerstown road and his left extending toward the Potomac, protected by General Stuart with the cavalry and horse artillery. General Walker, with his two brigades, was stationed on Longstreet's right. As evening approached, the enemy opened more vigorously with his artillery, and bore down heavily with his infantry upon Hood, but the attack was gallantly repulsed. At 10 p. m. Hood's