Jackson’s army corps bivouacked in the position they had held when the fierce musketry of Groveton died away.  It was not till long after daybreak on the 29th that his cavalry patrols discovered that King’s troops had disappeared, and that Longstreet’s advanced guard was already through Thoroughfare Gap.  Nor was it till the sun was high that Lee learned the events of the previous evening, and these threw only a faint light on the general situation.  But had either the Commander-in-Chief or his lieutenant, on the night of the 28th, known the true state of affairs, they would have had reason to congratulate themselves on the success of the plan which had been hatched on the Rappahannock.  They had anticipated that should Jackson’s movement on Manassas prove successful, Pope would not only fall back, but that he would fall back in all the confusion which arises from a hastily conceived plan and hastily executed manoeuvres.  They had expected that in his hurried retreat his army corps would lose touch and cohesion; that divisions would become isolated; that the care of his impedimenta, suddenly turned in a new direction, would embarrass every movement; and that the general himself would become demoralised.

The orders and counter-orders, the marches and counter-marches of August 28, and the consequent dispersion of the Federal army, are sufficient in themselves to prove the deep insight into war possessed by the Confederate leaders.

Nevertheless, the risk bred of separation which, in order to achieve great results, they had deliberately accepted had not yet passed away.  Longstreet had indeed cleared the pass, and the Federals who guarded it had retreated; but the main body of the Confederate army had still twelve miles to march before it could reach Jackson, and Jackson was confronted by superior numbers.  On the plateau of Bull Run, little more than two miles from the field of Groveton, were encamped over 20,000 Federals, with the main number at Manassas.  At Centreville, a seven miles’ march, were 18,000; and at Bristoe Station, about the same distance, 11,000.

It was thus possible for Pope to hurl a superior force against Jackson before Lee could intervene; and although it would have been sounder strategy, on the part of the Federal commander, to have concentrated towards Centreville, and have there awaited reinforcements, now fast coming up, he had some reason for believing that he might still, unaided, deal with the enemy in detail.  The high virtue of patience was not his.  Ambition, anxiety to retrieve his reputation, already blemished by his enforced retreat, the thought that he might be superseded by McClellan, whose operations in the Peninsula he had contemptuously criticised, all urged him forward.  An unsuccessful general who feels instinctively that his command is slipping from him, and who sees in victory the only hope of retaining it, seldom listens to the voice of prudence.

August 29.