The road upon which Porter marched was crowded during the night, so that he and his officers thought that they would make better time and be in better condition by marching at three A.M. He reached Bristoe at ten A.M., Kearny at eight, and Reno in due season. But it was late in the morning when McDowell was ready to march, and later in the day when his left swung out on the march to the Junction.
At twelve o’clock, General Pope reached Manassas Junction. Misled by the movements of A. P. Hill and Ewell, he ordered Reno’s corps and Kearny’s and Hooker’s divisions of the Third to Centreville, in search of Jackson, while the latter was little more than a league from him, resting quietly in his hiding-place, and his detached divisions had doubled on their courses and were marching to join him. McDowell, having information of my approach, delayed his march, detaching Ricketts’s division to hold me in check at Thoroughfare Gap.
The first passage at arms of the day was between part of Stuart’s cavalry, supported by B. T. Johnson’s infantry, and Meade’s brigade of McDowell’s command. As the latter swung around for his march to the Junction, the brigade approached Jackson’s right. A detachment was pushed out against Meade, and some artillery practice followed. The Confederates retired, but reported no loss. Under the impression that the force encountered was some cavalry rear-guard or reconnoitring party, McDowell resumed his march “as soon as the killed and wounded were cared for.”
The noise made by this affair caused Sigel to countermarch his corps, and otherwise delayed the march of McDowell’s entire forces, while it gave no inconvenience to the Confederates further than a change of front of part of Jackson’s command to receive battle, not intended, by his adversary. Jackson changed his front, but finding the direction of the enemy changed so as to march away from him, he took the move for a general retreat, made report of it to A. P. Hill, who was yet north of Bull Run, and ordered him to intercept the retreat by manning the lower fords of Bull Run. The order was received at ten A.M., but General Hill had intercepted despatches of General Pope giving notice of his preparation for battle at Manassas the next day, and thought it better to march on and join Jackson. He filed into line on Jackson’s left about noon.
General Jackson was right. If General Hill had moved as ordered, he would have met detachments ordered by General Pope to Centreville, and held them back to the south side until Jackson could join him to hold the line. The natural sequence of Confederate operations was position to intercept General Pope’s return to Washington. The scenes were shifting and inviting of adventure, and the marches should have followed them. General Hill was justified by the circumstances that influenced his march.
When General Pope reached the Junction with Heintzelman’s and Reno’s corps, the game was on other fields. As the last of the Confederate columns had hied away towards Centreville, he ordered thither those corps, and called up the Fifth to join him. He then changed the orders of McDowell’s column, directing it towards Centreville, to mass his cavalry, and find Jackson, and presently (at two P.M.) so far modified these as to direct McDowell to use his own judgment, and give him the benefit of his views, as he knew the country better, but ordered that he should not go farther towards Manassas Junction. These instructions were urgent, with assurances that McDowell’s moves should be supported by other columns. Had these been promptly executed, McDowell’s entire force should have encountered Jackson before four o’clock, but McDowell did not find Jackson. As his division, under King, marched along the turnpike a little before night, Jackson saw and engaged it in battle, as we shall see.
The head of my column reached Thoroughfare Gap early in the afternoon. Reports from General Jackson were that he was resting quietly on the flank of the enemy, and between him and Washington. Parties from the Gap reported it clear, and the Confederate commander called a rest for the night, but D. R. Jones’s division was ordered on to occupy the Gap.
As we approached it, officers riding to the front returned reporting the enemy coming in heavy columns on the other side. Jones was ordered to halt his division till he could advance his skirmishers. The Ninth Georgia Regiment, G. T. Anderson’s brigade, was sent and followed at proper distance by the division. The skirmishers met the enemy’s pickets in the Gap, drove them off, and followed till they in turn were met by a strong force and pushed back. The enemy’s leading brigade reached the plateau running along the eastern side of the mountain, which, with his batteries and infantry, gave him command at that end. Anderson reinforced his Ninth by the First, then by his other regiments on the mountain-side, to the left of the Gap, and advanced till arrested by the impenetrable tangle of the mountain undergrowth.
The Gap is a pass cut through Bull Run Mountain for the flow of a streamlet, through Occoquan Creek, to the waters of the Potomac. Its mean width is eighty yards. Its faces of basaltic rock rise in vertical ascent from one hundred to three hundred feet, relieved hither and thither by wild ivy, creeping through their fissures and from the tops of boulders in picturesque drapery. It was in the midst of this bold and beautiful scenery, in this narrow gorge where the Indians had doubtless often contested ages ago, that the seasoned soldiers of our civilized armies now battled for right of way.
Finding his passage over the mountain by the left side of the Gap blocked by the mountain tangle, Jones called up Toombs’s brigade, under command of Colonel Benning, and ordered it over the mountain obstacle by the south side. Drayton’s brigade was held in rear. By the time the troops were so disposed, Ricketts’s division was well deployed along the plateau on the east.