[McDowell in his testimony before the "Committee on the Conduct of the War," said: "At Fairfax Court House was the South Carolina Brigade. And I do not suppose anything would have had a greater cheering effect upon the troops, and perhaps upon the Country, than the capture of that brigade. And if General Tyler could have got down there any time in the forenoon instead of in the afternoon, the capture of that brigade was beyond question. It was about 5,000 or 6,000 men, and Tyler had 12,000, at the same time that we were pressing on in front. He did not get down there until in the afternoon; none of us got forward in time.">[
This slowness is due to various causes. There is a pretty general dread, for example, among our troops, of threatened ambuscades, and hence the advance is more cautious than it otherwise would be. It is thought the part of wisdom, as it were, to "feel the way." The marching, moreover, is new to our troops. General Scott had checked McDowell when the latter undertook to handle eight regiments together, near Washington, by intimating that he was "trying to make a show." Thus the very essential knowledge of how to manoeuvre troops in large bodies, has been withheld from our Union generals, while the volunteer regiments have either rusted in camp from inaction, or have been denied the opportunity of acquiring that endurance and hardiness and discipline which frequent movement of troops confers. Hence, all unused to the discipline of the march, every moment some one falls out of line to "pick blackberries, or to get water." Says McDowell, in afterward reporting this march: "They would not keep in the ranks, order as much as you pleased. When they came where water was fresh, they would pour the old water out of their canteens and fill them with fresh water; they were not used to denying themselves much."
Meantime, Heintzelman's Division is also advancing, by cross-roads, more to the left and South of the railroad line,—in accordance with McDowell's plan, which comprehends not only the bagging of Bonham, but an immediate subsequent demonstration, by Tyler, upon Centreville and beyond, while Heintzelman, supported by Hunter and Miles, shall swoop across Bull Run, at Wolf Run Shoals, some distance below Union Mills, turn the Enemy's right, and cut off his Southern line of railroad communications. Thus, by the evening of Wednesday, the 17th, Heintzelman is at Sangster's Station, while Tyler, Miles, and Hunter, are at Fairfax.
It is a rather rough experience that now befalls the Grand Army of the Union. All unused, as we have seen, to the fatigues and other hardships of the march, the raw levies, of which it almost wholly consists, which started bright and fresh, strong and hopeful, full of the buoyant ardor of enthusiastic patriotism, on that hot July afternoon, only some thirty hours back, are now dust-begrimed, footsore, broken down, exhausted by the scorching sun, hungry, and without food,—for they have wasted the rations with which they started, and the supply-trains have not yet arrived. Thus, hungry and physically prostrated, "utterly played out," as many of them confess, and demoralized also by straggling and loss of organization, they bivouac that night in the woods, and dream uneasy dreams beneath the comfortless stars.
A mile beyond Fairfax Court House, on the Warrenton Turnpike, is Germantown. It is here that Tyler's Division has rested, on the night of the 17th. At 7 o'clock on the morning of Thursday, the 18th, in obedience to written orders from McDowell, it presses forward, on that "Pike," to Centreville, five miles nearer to the Enemy's position behind Bull Run—Richardson's Brigade in advance—and, at 9 o'clock, occupies it. Here McDowell has intended Tyler to remain, in accordance with the plan, which he has imparted to him in conversation, and in obedience to the written instructions to: "Observe well the roads to Bull Run and to Warrenton. Do not bring on an engagement, but keep up the impression that we are moving on Manassas,"—this advance, by way of Centreville, being intended solely as a "demonstration" to mask the real movement, which, as we have seen, is to be made by the other divisions across Wolf Run Shoals, a point on Bull Run, some five or six miles below Union Mills, and some seven miles below Blackburn's Ford.
Upon the arrival of Richardson's Brigade, Thursday morning, at Centreville, it is found that, under cover of the darkness of the previous night, the Enemy has retreated, in two bodies, upon Bull Run, the one along the Warrenton Pike, the other (the largest) down the ridge-road from Centreville to Blackburn's Ford. Richardson's Brigade at once turns down the latter road and halts about a mile beyond Centreville, at a point convenient to some springs of water. Tyler soon afterward rides up, and, taking from that brigade two companies of light Infantry and a squadron of Cavalry, proceeds, with Colonel Richardson, to reconnoitre the Enemy, finding him in a strong position on the opposite bank of Bull Run, at Blackburn's Ford.
While this is going on, McDowell has ridden in a Southerly direction down to Heintzelman's Division, at Sangster's Station, "to make arrangements to turn the Enemy's right, and intercept his communications with the South," but has found, owing to the narrowness and crookedness of the roads, and the great distance that must be traversed in making the necessary detour, that his contemplated movement is too risky to be ventured. Hence he at once abandons his original plan of turning the Enemy's right, and determines on "going around his left, where the country is more open, and the roads broad and good."
McDowell now orders a concentration, for that night, of the four divisions, with two days cooked rations in their haversacks, upon and about Centreville,—the movement to commence as soon as they shall receive expected commissariat supplies. But, later on the 18th,—learning that his advance, under Tyler, has, against orders, become engaged with the Enemy—he directs the concentration to be made at once.
Let us examine, for a moment, how this premature engagement comes about. We left Tyler, accompanied by Richardson, with a squadron of Cavalry and a battalion of light Infantry making a reconnaissance, on Thursday morning the 18th, toward Blackburn's Ford. They approach within a mile of the ford, when they discover a Rebel battery on the farther bank of Bull Run—so placed as to enfilade the road descending from their own position of observation down to the ford,—strong Rebel infantry pickets and skirmishing parties being in front.
Tyler at once orders up his two rifled guns, Ayres' Battery, and Richardson's entire Brigade—and later, Sherman's Brigade as a reserve. As soon as they come up,—about noon—he orders the rifled guns into battery on the crest of the hill, about one mile from, and looking down upon, the Rebel battery aforesaid, and opens upon the Enemy; giving him a dozen shells,—one of them making it lively for a body of Rebel Cavalry which appears between the ford and Manassas.