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.