the 14th instant, and marched to Middletown and beyond, where it was halted about 1 p. m. of that day. General Reno's corps being in front and engaged with the enemy, about 2 p. m. the division was ordered to the front to his support. The enemy was disputing our passage over the turnpike through the South Mountain, and had been attacked on the left by General ReNumbers After some consultation with the general commanding the right wing and the corps, I was directed to move the division on a road leading off to the right of the turnpike and toward the enemy's left. After advancing over a mile on this road, the division, which was the advance of the corps, was turned across the field to the left, and moved in an advantageous position to support Cooper's battery, which it was proposed to establish on an adjoining eminence.

The enemy, perceiving these dispositions, opened on the column from a battery on the mountain side, but without inflicting any injury. Captain Cooper's battery of 3-inch ordnance guns was immediately put in position on the ridge above referred to, and at the same time, by direction of the general commanding the corps, the regiment of First Rifles of the division was sent forward as skirmishers to feel for the enemy. Being well satisfied, from various indications, that the enemy occupied the mountain in force with his infantry, the general commanding the corps directed me to advance my division to the right, so as, if possible, to outflank them, and then to move forward to attack him. a slight description of the features of the ground is necessary to properly describe the movements of the division. The turnpike from Fredericktown to Hagerstown in crossing the mountains takes a general direction of northwest and southeast. The mountain ridge occupied by the enemy was perpendicular in its general direction to the road. Parallel to the mountain was another ridge, separated from it at the turnpike ba a deep valley, but connected at the upper end by a very small depression. Over this second ridge there was a road, along which I advanced Seymour's brigade of the division, directing him to push forward and feel the enemy.

Soon after advancing, General Seymour reported that he could take the crest of the first ridge, along which ran the road, and could then advance across the ravine to the second ridge, which I immediately ordered him to do. At the same time I deployed Gallagher's (Third) brigade parallel to the mountain, and also Magilton's (Second) brigade on the same line, but down in the valley, and, when the line of battle was completely formed, directed a general advance of the whole. Seymour soon gained the crest of the first ridge, and then moved in the same direction as the other two bridages. Gallagher and Magilton advanced steadily to the foot of the mountain, where they found the enemy's infantry. In a short time the action became general throughout the whole line. Steadily the line advanced up the mountain side, where the enemy was posted behind trees and rocks, from whence he was slowly, but gradually, dislodged, Seymour first gaining the crest of the hill, and driving the enemy to the left along the ridge, where he was met with the fire of the other two brigades. Soon after the action commenced, having reason to believe the enemy was extending his left flank to flank us, I sent to the general commanding the corps for reenforcements, which were promptly furnished by sending General Duryea's brigade of Ricketts' division. Owing, however, to the distance to be traveled to reach the scene of action, Duryea did not arrive on the ground till just at the close of the engagement. His men were promptly formed in line of battle, and advanced on the left of Seymour, but only one regiment had on opportunity to open fire before the enemy retired and darkness intervened.