skirmishers of the Pennsylvania Reserves. The whole of General Hooker's corps was soon engaged, and drove the enemy from the open field in front of the first line of woods into a second line of woods beyond, which runs to the eastward of and nearly parallel to the Sharpsburg and Hagerstown turnpike.

This contest was obstinate, and as the troops advanced the opposition became more determined and the number of the enemy greater. General Hooker the ordered up the corps of General Mansfield, which moved promptly toward the scene of action.

The First Division, General Williams', was deployed to the right on approaching the enemy; General Crawford's brigade on the right, its right resting on the Haagerstown turnpike; on his left General Gordon's brigade. The Second Division, General Greene's, joining the left of Gordon's, extended as far as the burned building to the northeast of the white church on the turnpike. During the deployment, that gallant veteran, General Mansfield, fell mortally wounded while examining the ground in front of his troops. General Hartsuff, of Hooker's corps, was taken from the field.

The command of the Twelfth Corps fell upon General Williams. Five regiments of the First Division of this corps were new troops. One brigade of the Second Division was sent to support General Doubleday.

The One hundred and twenty-fourth Pennsylvania Volunteers were pushed across the turnpike into the woods beyond J. Miller's house, with orders to hold the position as long as possible.

The line of battle of this corps was formed, and it became engaged about 7 a.m., the attack being opened by Knap's (Pennsylvania), Cothran's (New York), and Hampton's (Pittsburgh) batteries. To meet this attack the enemy had pushed a strong column of troops into the open fields in front of the turnpike, while he occupied the woods on the west of the turnpike in strong force. The woods (as was found by subsequent observation) were traversed by outcropping ledges of rock. Several hundred yards to the right and rear was a hill which commanded the debouche of the woods, and in the fields between was a long line of stone fences, continued by breastworks of rails, which covered the enemy's infantry from our musketry. The same woods formed a screen, behind which his movements were concealed, and his batteries on the hill and the rifle-works covered from the fire of our artillery in front. For about two hours the battle raged with varied success, the enemy endeavoring to drive our troops into the second line of wood, and ours in turn to get possession of the line if front. Our troops ultimately succeeded in forcing the enemy back into the woods near the turnpike, General Greene with his two brigades crossing into the woods to the left of the Dunker Church. During this conflict General Crawford, commanding the First Division after General Williams took command of the corps, was wounded, and left the field.

General Greene being much exposed and applying for re-enforcements, the Thirteenth New Jersey, Twenty-seventh Indiana, and the Third Maryland were sent to his support, with a section of Knap's battery.

At about 9 o'clock a.m. General Sedgwick's division of General Sumner's corps arrived. Crossing the ford previously mentioned, this division marched in three columns to the support of the attack on the enemy's left. On nearing the scene of action the columns were halted, faced to the front, and established by General Sumner in three parallel lines by brigade, facing toward the south and west; General Gorman's brigade in front, General Dana's second, and General Howard's third.