No. 43. Report of Colonel Samuel P. Heintzelman, Seventeenth U. S. Infantry, commanding Third Division.

HDQRS. 3rd DIV. DEP'T NORTHEASTERN VIRGINIA, Washington, July 31, 1861.

SIR: In obedience to instructions received on the 20th instant, the division under my command was under arms in light marching order, with two days' cooked rations in their haversacks, and commenced the march at 2.30 a.m. on the 21st, the brigade of Colonel Franklin leading, followed by those of Colonels Willcox and Howard. At Centreville we found the road filled with troops, and were detained three hours to allow the division of General Tyler and Colonel Hunter to pass. I followed with my division immediately in rear of the latter. Between two and three miles beyond Centreville we left we Warrenton turnpike, turning into a country road on the right. Captain Wright, of the Engineers, accompanied the head of Colonel Hunter's column, with directions to stop at a road which turned in to the left to a ford across Bull Run, about half way between the point where we turned off from the turnpike and Sudley Springs, at which letter point Colonel Hunter's division was to cross. No such road was found to exist, and about 11 a.m. we found ourselves at Sudley Springs, about ten miles from Centreville, with one brigade of Colonel Hunter's division still on our side of the run.

Before reaching this point the battle had commenced. We could see the smoke rising on our left from two points, a mile or more apart. Two clouds of dust were seen, showing the advance of troops from the direction of Manassas. At Sudley Springs, whilst waiting the passage of the troops of the division in our front, I ordered forward the First Brigade to fill their canteens. Before this was accomplished the leading regiments of Colonel Hunter's division became engaged. General McDowell, who, accompanied by his staff, had passed us a short time before, sent back Captain Wright, of the Engineers, and Major McDowell, one of his aides, with orders to send forward two regiments to prevent the enemy from outflanking them. Captain Wright led forward the Minnesota regiment to the left of the road which crossed the run at this place. Major McDowell led the Eleventh Massachusetts Regiment up the road. I accompanied this regiment, leaving orders for the remainder of the division to follow, with the exception of Arnold's battery, which, supported by the First Michigan, was posted a little below the crossing of the run as a reserve.

At a little more than a mile from the ford we came upon the battle-field. Rickett's battery was posted on a hill to the right of Hunter's division and to the right of the road. After firing some twenty minutes at a battery of the enemy placed just beyond the crest of a hill on their extreme left, the distance being considered too great, it was moved forward to within about one thousand feet of the enemy's battery. Here it was exposed to a heavy fire of musketry, which soon disabled the battery. Franklin's brigade was posted on the right of a woods near the center of our line, and on ground rising towards the enemy's position. In the man I sent orders for the zouaves to move forward, to support Ricketts' battery on its right. As soon as they came up I led them forward against and Alabama regiment, partly concealed in a clump of small pines in and old field. At the first fire they broke, and the greater portion fled to the rear, keeping up a desultory firing over the heads of