At noon, however, the attack came to a halt, partly through the fatigue of the troops, partly because the advancing line, having swept the field for nearly a mile, found itself in a valley, from which further progress had to be made with all the advantage of the ground in favor of the enemy.  In the lull of the conflict which for a while ensued, the Confederate commander, with little hope except to mitigate a defeat, hurriedly concentrated his remaining artillery and supporting regiments into a semicircular line of defense at the top of the hill that the Federals would be obliged to mount, and kept them well concealed among the young pines at the edge of the timber, with an open field in their front.

Against this second position of the enemy, comprising twelve regiments, twenty-two guns, and two companies of cavalry, McDowell advanced in the afternoon with an attacking force of fourteen regiments, twenty-four guns, and a single battalion of cavalry, but with all the advantages of position against him.  A fluctuating and intermitting attack resulted.  The nature of the ground rendered a combined advance impossible.  The Union brigades were sent forward and repulsed by piecemeal.  A battery was lost by mistaking a Confederate for a Union regiment.  Even now the victory seemed to vibrate, when a new flank attack by seven rebel regiments, from an entirely unexpected direction, suddenly impressed the Union troops with the belief that Johnston’s army from Harper’s Ferry had reached the battle-field; and, demoralized by this belief, the Union commands, by a common impulse, gave up the fight as lost, and half marched, half ran from the field.  Before reaching Centreville, the retreat at one point degenerated into a downright panic among army teamsters and a considerable crowd of miscellaneous camp-followers; and here a charge or two by the Confederate cavalry companies captured thirteen Union guns and quite a harvest of army wagons.

When the truth came to be known, it was found that through the want of skill and courage on the part of General Patterson in his operations at Harper’s Ferry, General Johnston, with his whole Confederate army, had been allowed to slip away; and so far from coming suddenly into the battle of Bull Run, the bulk of them were already in Beauregard’s camps on Saturday, and performed the heaviest part of the fighting in Sunday’s conflict.

The sudden cessation of the battle left the Confederates in doubt whether their victory was final, or only a prelude to a fresh Union attack.  But as the Union forces not only retreated from the field, but also from Centreville, it took on, in their eyes, the proportions of a great triumph; confirming their expectation of achieving ultimate independence, and, in fact, giving them a standing in the eyes of foreign nations which they had hardly dared hope for so soon.  In numbers of killed and wounded, the two armies suffered about equally; and General Johnston writes:  “The Confederate army was more disorganized by victory than that of the United States by defeat.”  Manassas was turned into a fortified camp, but the rebel leaders felt themselves unable to make an aggressive movement during the whole of the following autumn and winter.