I claim credit for the officers of my staff and for those acting as such during the day. They did everything in their power, exposing themselves freely when required, and doing all that men could do, communicating orders, guiding the columns, exhorting the troops, rallying them when broken, and providing for them the best the circumstances admitted.

They are as follows:

First Lieut. H. W. Kingsbury, Fifth Artillery, A, D.C.

Maj. Clarence S. Brown, New York Militia, volunteer A.D.C. Maj. James S. Wadsworth, New York Militia, volunteer A.D.C.

The latter (who does me the honor to be on my personal staff) had a horse shot under him in the hottest of the fight.

Capt. James B. Fry, assistant adjutant-general.

Capt. O. H. Tillinghast, assistant quartermaster, who discharged alone the important and burdensome duties of his department with the Army, and who was mortally wounded whilst acting with the artillery, to which he formerly belonged, and in which he was deeply interested.

Capt. H. F. Clarke, Subsistence Department, chief of subsistence department.

Major Myer, Signal Officer, and Maj. Malcolm McDowell, who acted as aides.

Surg. W. S. King and Assistant Surgeon Magruder, Medical Department.

Maj. J. G. Barnard, Engineer, and senior of his department with the Army, who gave me most important aid.

First Lieut. Fred. E. Prime, Engineer.

Capt. A. W. Whipple, First Lieut. H. L. Abbot, and Second Lieut. H. S. Putnam, Topographical Engineers.

Maj. W. F. Barry, Fifth Artillery, chief of artillery.

Lieut. Geo. C. Strong, ordnance officer.

Maj. W. H. Wood, Seventeenth Infantry, acting inspector-general.

Second Lieut. Guy V. Henry, who joined me on the field, and was of service as an aide-de-camp.

The following officers commanded divisions and brigades, and in the several places their duty called them did most effective service and behaved in the most gallant manner:

Brigadier-General Tyler, Connecticut Volunteers.

Col. David Hunter, Third Cavalry, severely wounded at the head of his division.

Col. S. P. Heintzelman, Seventeenth Infantry, wounded in the arm while leading his division into action on the hill.

Brigadier-General Schenck, Ohio Volunteers, commanding Second Brigade, First Division.

Col. E. D. Keyes, Eleventh Infantry, commanding First Brigade, First Division.

Col. W. B. Franklin, Twelfth Infantry, First Brigade, Third Division.

Col. W. T. Sherman, Thirteenth Infantry, commanding Third Brigade, First Division.

Col. Andrew Porter, Sixteenth Infantry, commanding First Brigade, Second Division.

Col. A. E. Burnside, Rhode Island Volunteers, commanding Second Brigade, Second Division.

Col. O. B. Willcox, Michigan Volunteers, commanding Second Brigade, Third Division, who was wounded and taken prisoner whilst on the hill in the hottest of the fight.

Col. O. O. Howard, Maine Volunteers, commanding Third Brigade, Third Division.

Col. I. B. Richardson, Michigan Volunteers, commanding Fourth Brigade, First Division.

Colonel Blenker, New York Volunteers, commanding First Brigade, Fifth Division.

Colonel Davies, New York Volunteers, commanding Second Brigade, Fifth Division.

As my position may warrant, even if it does not call for, some explanation of the causes, as far as they can be seen, which led to the results herein stated, I trust it may not be considered out of place if I refer, in a few words, to the immediate antecedents of the battle.

When I submitted to the General-in-Chief, in compliance with his verbal instructions, the plan of operations and estimate of force required, the time I was to proceed to carry it into effect was fixed for the 8th of July (Monday).

Every facility possible was given me by the General-in-Chief and heads of the administrative departments in making the necessary preparations. But the regiments, owing, I was told, to want of transportation, came over slowly. Many of them did not come across until eight or nine days after the time fixed upon, and went forward without my ever seeing them and without having been together before in a brigade.

The sending re-enforcements to General Patterson by drawing off the wagons was a further and unavoidable cause of delay.

Notwithstanding the herculean efforts of the Quartermaster-General, and his favoring me in every possible way, the wagons for ammunition, subsistence, &c., and the horses for the trains and for the artillery, did not all arrive for more than a week after the time appointed to move.

I was not even prepared as late as the 15th ultimo, and the desire I should move became great, and it was wished I should not, if possible, delay longer than Tuesday, the 16th ultimo. When I did set out on the 16th I was still deficient in wagons for subsistence, but I went forward, trusting to their being procured in time to follow me.

The trains thus hurriedly gotten together, with horses, wagons, drivers, and wagon-masters all new and unused to each other, moved with difficulty and disorder, and was the cause of a day's delay in getting the provisions forward, making it necessary to make on Sunday the attack we should have made on Saturday.

I could not, with every exertion, get forward with the troops earlier than we did. I wished them to go to Centreville the second day, which would have taken us there on the 17th, and enabled us, so far as they were concerned, to go into action on the 19th instead of the 21st; but when I went forward from Fairfax Court-House beyond Germantown to urge them forward, I was told it was impossible for the men to march farther. They had only come from Vienna, about six miles, and it was not more than six and one-half miles farther to Centreville, in all a march of twelve and one-half miles; but the men were foot-weary, not so much, I was told, by the distance marched, as by the time they had been on foot, caused by the obstructions in the road and the slow pace we had to move to avoid ambuscades. The men were, moreover, unaccustomed to marching, their bodies not in condition for that kind of work, and not used to carrying even the lead of "light marching order."

We crossed Bull Run with about 18,000 men of all arms, the Fifth Division (Miles') and Richardson's brigade on the left at Blackburn's Ford and Centreville, and Schenck's brigade of Tyler's division on the left of the road near the stone bridge, not participating in the main action. The numbers opposed to us have been variously estimated. I may safely say, and avoid even the appearance of exaggeration, that the enemy brought up all he could which were not kept engaged elsewhere. He had notice of our coming on the 17th, and had from that time until the 21st to bring up whatever he had.

It is known that in estimating the force to go against Manassas I engaged not to have to do with the enemy's forces under Johnston, then kept in check in the valley by Major General Patterson, or those kept engaged by Major-General Butler, and I knew every effort was made by the General-in-Chief that this should be done, and that even if Johnston joined Beauregard, it should be because he would be driven in and followed by General Patterson. But, from causes not necessary for me to refer to, even if I knew them all, this was not done, and the enemy was free to assemble from every direction in numbers only limited by the amount of his railroad rolling-stock and his supply of provisions. To the forces, therefore, we drove in from Fairfax Court-House, Fairfax Station, Germantown, and Centreville, and those under Beauregard at Manassas, must be added those under Johnston from Winchester, and those brought up by Davis from Richmond and other places at the South, to which is to be added the levy en masse ordered by the Richmond authorities, which was ordered to assemble at Manassas. What all this amounted to I cannot say; certainly much more than we attacked them with.

I could not, as I have said, move earlier or push on faster, nor could I delay. A large and the best part, so considered, of my forces were three-months' volunteers, whose terms of service were about expiring, but who were sent forward as having long enough to serve for the purpose of the expedition.

On the eve of the battle the Fourth Pennsylvania Regiment of Volunteers and the battery of Volunteer Artillery of the Eighth New York Militia, whose term of service expired, insisted on their discharge. I wrote to the regiment as pressing a request as I could pen, and the honorable Secretary of War, who was at the time on the ground, tried to induce the battery to remain at least five days, but in vain. They insisted on their discharge that night. It was granted; and the next morning, when the Army moved forward into battle, these troops moved to the rear to the sound of the enemy's cannon.

In the next few days, day by day I should have lost ten thousand of the best armed, drilled, officered, and disciplined troops in the Army. In other words, every day which added to the strength of the enemy made us weaker.

In conclusion, I desire to say in reference to the events of the 21st ultimo, that the general order for the battle to which I have referred was, with slight modifications, literally conformed to; that the corps were brought over Bull Run in the manner proposed, and put into action as before arranged, and that, up to late in the afternoon, every movement ordered was carrying us successfully to the object we had proposed before starting--that of getting to the railroad leading from Manassas to the valley of Virginia, and going on it far enough to break up and destroy the communication, and interpose between the forces under Beauregard and those under Johnston; and could we have fought a day-yes, a few hours-sooner, there is everything to show that we should have continued successful, even against the odds with which we contended.

I have the honor to be, very respectfully, your most obedient servant,

IRWIN McDOWELL,
Brigadier-General, Commanding.

Lieut. Col. E. D. TOWNSEND,
Asst. Adjt. Gen., Hdqrs. of the Army, Washington, DC