Rebellion Record: a Diary of American Events: Documents and Narratives, Volume 2.
Frank Moore, Ed.

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 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 the heads of the administrative departments, in making the necessary preparations. But the regiments, owing, I was told, to a want of transportation, came over slowly. Many of them did not come across till eight or nine days after the time fixed upon, and went forward without my even seeing them, and without having been together before.in a brigade. The sending reinforcements 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 way, the wagons for ammunition, subsistence, &c., and the horses for the trains and the artillery, did not 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 gathered together, with horses, wagons, drivers, and wagon managers, 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 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 further. They had only come from Vienna, about six miles, and it was not more than six and a half miles farther to Centreville — in all a march of twelve and a 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 carying even the load of light marching order.

We crossed Bull Run with about 18,000 men of all arms, the fifth division (Miles's and Richardson's brigade) on the left, at Blackburn's Ford to 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 know every effort was made by the General-in-Chief that this should be done, and that even if Johnston joined Beauregard, it would not be because he could be followed by General Patterson, but from causes not necessary for me to refer to, you 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, to 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, more early push on faster, nor could I delay. A large and the best part of my forces were three months volunteers, whose term of service was about to expire, 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 New York Eighth militia, whose term of service expired, insisted on their discharge. I wrote to the regiment, expressing a request for them to remain a short time, and the Hon. 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