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

It is intended to turn the position, force the enemy from the road, that it may be reopened, and, if possible, destroy the railroad leading from Manassas to the valley of Virginia, where the enemy has a large force. As this may be resisted by all the force of the enemy, the troops will be disposed as follows:

The first division (General Tyler's) with the exception of Richardson's brigade, will, at half-past 2 o'clock in the morning precisely, be on the Warrenton turnpike to threaten the passage of the bridge, but will not open fire until full daybreak.

The second division (Hunter's) will move from its camp at two o'clock in the morning precisely, and, led by Captain Woodbury, of the Engineers, will, after passing Cub Run, turn to the right and pass the Bull Run stream above the ford at Sudley's Spring, and then turning down to the left, descend the stream and clear away the enemy who may be guarding the lower ford and bridge. It will then bear off to the right and make room for the succeeding division.

The third division (Heintzelman's) will march at half-past 2 o'clock in the morning, and follow the road taken by the second division, but will cross at the lower ford after it has been turned as above, and then, going to the left, take place between the stream and second division.

The fifth division (Miles's) will take position on the Centreville Heights, (Richardson's brigade will, for the time, form part of the fifth division, and will continue in its present position.) One brigade will be in the village, and one near the present station of Richardson's brigade. This division will threaten the Blackburn Ford, and remain in reserve at Centreville. The commander will open fire with artillery only, and will bear in mind that it is a demonstration only he is to make. He will cause such defensive works, abatis, earthworks, &c., to be thrown up as will strengthen his position. Lieutenant Prime, of the Engineers, will be charged with this duty.

These movements may lead to the gravest results, and commanders of divisions and brigades should bear in mind the immense consequences involved. There must be no failure, and every effort must be made to prevent straggling.

No one must be allowed to leave the ranks without special authority. After completing the movements ordered, the troops must be held in order of battle, as they may be attacked at any moment.

By command of

In my communication to you of the 20th ult., I stated it as my intention to move that afternoon, and drive the enemy from the east side of Bull Run, so as to enable the engineers to make a sufficiently accurate reconnoissance to justify our future movements. Later in the day they had obtained enough information of the passage across the stream to dispense with this reconnoissance, and it was decided to move without delay. It had been my intention to move the several columns out on the road a few miles on the evening of the 20th, so that they would have a shorter march in the morning; but I deferred to those who had the greatest distance to go, and who preferred starting early in the morning, and making but one move.

On the evening of the 20th ultimo my command was mostly at or near Centreville. The enemy was at or near Manassas, distant from Centreville about seven miles to the southwest. Centreville is a village of a few houses, mostly on the west side of a ridge running nearly north and south. The road from Centreville to Manassas junction was along this ridge, and crosses Bull Run about three miles from the former place. The Warrenton turnpike, which runs nearly east and west, goes over this ridge, through the village, and crosses Bull Run about four miles from it, Bull Run having a course between the crossing from northwest to southeast. The first division (Tyler's) was stationed on the north side of the Warrenton turnpike, and on the eastern slope of the Centreville ridge, two brigades on the same road, and a mile and a half in advance, to the west of the ridge, and one brigade on the road from Centreville to Manassas, where it crosses Bull Run at Blackburn's Ford, where General Tyler had the engagement of the 18th ultimo. The second division (Hunter's) was on the Warrenton turnpike, one mile east of Centreville. The third division (Heintzelman's) was on a road known as the Old Braddock road, which comes into Centreville from the southeast, about a mile and a half from the village. The fifth division (Miles's) was on the same road with the third division, and between it and Centreville. A map which is herewith, marked A, will show these positions better than I can describe them.

On Friday night a train of subsistence arrived, and on Saturday its contents were ordered to be issued to the command, and the men required to have three days rations in their haversacks. On Saturday orders were issued for the available force to march. As reported to you in my letter of the 19th ultimo, my personal reconnoissance of the roads to the south had shown that it was not practicable to carry out the original plan of turning the enemy's position on their right. The affair of the 18th at Blackburn's Ford showed he was too strong at that point for us to force a passage there without great loss, and if we did, that it would bring us in front of his strong position at Manassas, which was not desired. Our information was that the stone bridge over which the Warrenton road crossed Bull Run, to the west of Centreville, was defended by a battery in position, and the road on his side of the stream impeded by a heavy abatis. The alternative was, therefore, to turn the extreme left of his position. Reliable information was obtained of an undefended ford about three miles above the bridge, there being another fiord between it and the bridge, which was defended. It was therefore determined to take the road to the upper ford, and after crossing, to get behind the forces guarding the lower ford and the bridge, and after occupying the Warrenton road east of the bridge, to send out a force to destroy the railroad at or near Gainesville, and thus break up the communication between the enemy's forces at Manassas and those in the valley of Virginia, before Winchester, which had been held in check by Major-General Patterson.

Brigadier-General Tyler was directed to move with three of his brigades on the Warrenton road, and commence cannonading the enemy's batteries, while Hunter's division, moving after him, should, after passing a little stream called Cub Run, turn to the right and north, and move around to the upper ford, and there turn south and get behind the enemy.