HEADQUARTERS FIRST BRIGADE, REGULAR INFANTRY, Camp near Hall's Hill, Va., September 6, 1862.

SIR: I have the honor to submit the following report of the operations of my brigade, composed of the Third, Fourth, and First Battalions of the Twelfth, and First and Second Battalions of the Fourteenth Infantry, on the 30th ultimo, at Bull Run and in its vicinity:

At daylight on the morning of the 30th we took up our line of march

from our bivouac on the Manassas and Gainesville road in the direction of Bull Run and reached that stream about 10 a. m., soon after which I was ordered to place my brigade in position in the field fronting the Dogan house. The First and Second Battalions of the Fourteenth were deployed in a corn field, with the Twelfth and Fourth Infantry covering them in their rear in columns of battalions, the left of our line resting on the Warrenton turnpike. The Third was advanced to the front and right under cover of a wood, about 1,000 yards distant, where it was deployed as skirmishers.

About 11 a. m. the enemy commenced throwing shells into us from a battery beyond the wood in front of the Third, killing 1 man and wounding several. Butterfield's brigade, which had previously been placed in position on my right, was soon advanced into the wood, and I was directed to advance the four battalions to the front and obliquely to the right, to take up a position in rear and under cover of the woods, which I did in column of battalions, left in front. As soon as notified that I was unmasked by Butterfield I advanced the two battalions of the Fourteenth into and through the woods to his support, and held them there until after his brigade was entirely withdrawn, when my whole column was ordered to the rear. While in the woods we were under a most incessant fire of all arms, but my officers and men behaved admirably. Here it was that Captain O'Connell, of the Fourteenth Infantry, was wounded in the knee while commanding the First Battalion (notwithstanding which he continued with his command throughout the day), and Captain D. B. McKibbin, Fourteenth Infantry, in the ear, while commanding the Second Battalion.

The Third Infantry, meanwhile, had been advanced, and held possession for several hours of two houses, about 100 and 250 yards in front and to the left of the wood, which it held until all the troops were withdrawn from the center. In withdrawing the Third the right wing united with the brigade, and the left, being across the turnpike, united with Warren's brigade, and served with it until the whole division was united on the plateau between the Henry and Robinson houses.

About 5 p. m. the brigade was withdrawn from the wood in admirable order, moving by the fronts of battalions in column, and halted for a short time in rear of Weed's battery, on a line with the Dogan house. From this point I was ordered across the turnpike to a position on the plateau between the Henry and Robinson houses, where the brigade was deployed in line of battle, with its right resting on the Henry house.

About 6 p. m. I was ordered to take the battalion of the Twelfth and Fourteenth to a wood to our left and front, to support Meade's brigade, then severely pressed by the enemy; and almost immediately after placing these troops in position I observed that the Third and Fourth had also been ordered up. I found the enemy in very strong force in the wood, and during the heat of a very severe engagement discovered that he was flanking me with large masses of troops. I immediately commenced to gain ground to my left, so as to meet his movements, and held him in check for nearly an hour. But at length I found the contest too unequal; my command was being cut to pieces; the ammunition of the men nearly expended, and, the enemy's masses vastly outnumbering my force, I was forced to give the order to retire. This was done in most excellent order, the men marching steadily and slowly, and I resumed my position on the plateau. Shortly after I was ordered to retire with my brigade to Centreville, which I did, and reached that

point at 1 o'clock at night, having the entire brigade with me in good order and having left but few stragglers behind.

I cannot omit calling the attention of the brigadier-general commanding to the firm and gallant manner in which my brigade held the enemy in check on the extreme left for such a length of time and finally prevented his turning our flank. At one time the Third and Fourth were within 30 yards of one of his brigades, which made a flank movement to turn their left, when Captain Dryer, commanding the Fourth, gave orders to fire by battalions, and poured three most destructive volleys into it before his fire could be returned. The greatest portion of my loss was at this point, and too much credit cannot be given to officers and men for their coolness and gallantry during this engagement. The Second Battalion of the Fourteenth was under fire for the first time and behaved admirably.

I must beg leave to call attention to Captain Wilkins, commanding Third Infantry; Captain J. B. Collins, commanding the Fourth, wounded, who was succeeded in the command by Captain H. Dryer, this latter officer being especially conspicuous for his coolness and gallantry; Captain J. D. O'Connell, Fourteenth Infantry, commanding First Battalion, severely wounded in several places and behaving most gallantly; and Captain D. B. McKibbin, Fourteenth Infantry, commanding Second Battalion, Fourteenth, who displayed conspicuous gallantry throughout.

Captain Wilkins, Third Infantry, mentions Captain Walker, acting field officer, for coolness and the prompt carrying out of his orders; Lieutenants Sheridan, Whitney, Eckert, and Penrose; Lieutenant Devoe, adjutant, who rendered important services, and behaved with the same indifference to danger which has distinguished him on former occasions. Sergt. Major A. Kaiser, Sergeants Torpy, Mourton, Hopkins, Litzinger, Smith, Hessian, Coady, Schafer, Morris, Hanley, Flynn, Ackland, and Scully, of the Third Infantry, and Sergt. George Lamonion, of the Twelfth Infantry, are especially mentioned.

I would particularly mention my staff-Second Lieutenant W. H. Powell, Fourth Infantry, acting assistant adjutant-general and aide-de-camp, First Lieutenant S. Van Rensselaer, Twelfth Infantry. These officers behaved with the utmost coolness and gallantry, and carried my orders to every part of the field to which they were sent with cheerfulness and alacrity.

My whole brigade behaved as well as I could have expected or desired, and has, I trust, earned the favorable notice of the brigadier-general commanding the division.

I am, sir, respectfully, your obedient servant,

ROBT. C. BUCHANAN,

Lieutenant-Colonel, Fourth Infantry, Commanding Brigade.

First Lieutenant HEYWARD CUTTING,

Acting Assistant Adjutant-General, Sykes' Division.