HDQRS. SEMMES' BRIGADE, McLAWS' DIVISION, Camp near Martinsburg, W. Va., September 24, 1862.

MAJOR: I have the honor to report briefly the part enacted by my brigade, composed of the Fifteenth and Thirty-second Virginia and the Tenth and Fifty-third Georgia Volunteers, and Manly's battery, in the battle of Sharpsburg, on September 17:

Moving forward by the flank in the direction of the enemy, before coming in view, two brigades were met retiring from the front apparently badly cut up. An incessant current of wounded flowed to the rear, showing that the conflict had been severe and well contested. Coming in full view, of the enemy's line, Major-General McLaws, in person, ordered me to move forward in line to the support of Major-General Stuart, on our extreme left. Immediately the order was given, "by company into line," followed by "forward into line," both of which movements were executed, in the presence of the enemy, under a fire occasioning severe loss in killed and wounded. The brigade advanced steadily for 200 yards under fire before the order was given to commence firing. This order was then given at long range for most of our arms, for the purpose of encouraging our troops and disconcerting the enemy. The troops, it is true, needed little encouragement. Their officers had already inspired them with enthusiasm, and they continued to advance with vivacity. The effect on the enemy's fire of the order to the regiments of the brigade that had formed in line to commence firing was distinctly visible in the diminished numbers of killed and wounded. The enemy at first met our advance by a corresponding one. Our troops continued to press steadily forward, pouring a deadly fire into his ranks, and he, after advancing 100 yards, gave way; and we continued to drive him from position to position, through wood and field for a mile, expending not less than 40 rounds of ammunition. My brigade was thrown farther to the front than the troops on my right by about 300 yards, and for a time was exposed to a terrible front and enfilading fire, inflicting great loss.

It gives me satisfaction to be enabled to state that my brigade fought under an inspiration of enthusiasm which impelled the men forward with the confidence of victory. Had it been possible to have strengthened it by a supporting force of 2,000 or 3,000 men, there was not then, nor is there now, a doubt in my mind that the enemy's right, though in vastly superior numbers, would have been driven upon his center and both, in confusion, on his left, utterly routing him. The victory, though decisive, would thus have been rendered signal, and the enemy's lines broken and dispersed.

The loss in killed and wounded was, of the Fifty-third Georgia Volunteers, 30 per cent.; Thirty-second Virginia, 45 per cent.; Tenth Georgia, 57 per cent.; Fifteenth Virginia, 58 per cent., detailed statements of which are herewith submitted. The disparity in the loss of some of the companies of the same regiment is very marked. Three of the four regimental commanders were wounded. Lieutenant-Colonel Sloan, commanding Fifty-third Georgia, fell it, was then supposed, mortally wounded, while gallantly leading his regiment forward into line on the extreme left of the brigade.

The regimental commanders displayed conspicuous gallantry, and by their example inspired their commands with the confidence of positive success. Troops never fought more persistently, intelligently, and with more valor.

My staff, Lieutenant Briggs, aide-de-camp, and Lieutenants Redd and