eral withdrew his forces during the night of the 27th and morning of the 28th toward Sudley and Groveton. He was followed by Heintzelman and Reno, via Centreville; and McDowell and Sigel, after having marched some distance toward Manassas, were ordered to direct their march toward Centreville. In this movement toward Centreville King's division of McDowell's corps struck the right of Jackson's force late in the afternoon, just north of the Warrenton turnpike, a mile west of Groveton. A sharp contest ensued, lasting until some time after dark, when King still held his ground on the turnpike. Reynolds was then near the right of King, Sigel on his right near the stone house, Heintzelman and Reno near Centreville; Ricketts, who had been sent in the morning to Thoroughfare Gap, was disputing with Longstreet the passage of the Gap.

Thus it was still hoped to strike Jackson a decisive blow on the morning of the 29th before re-enforcements could reach him. In the mean time the Confederate general had taken up a favorable position a little to the north and west of Groveton and Sudley to await attack.

Under these conditions General Porter, who was still at Bristoe Station, received, at 6 a. m., the following order from General Pope:

HEADQUARTERS ARMY OF VIRGINIA, Near Bull Run, August 29, 1862-3 a. m.

Major-General PORTER:

GENERAL: McDowell has intercepted the retreat of Jackson. Sigel is immediately on the right of McDowell. Kearny and Hooker march to attack the enemy's rear at early down. Major-General Pope directs you to move upon Centreville at the first dawn of day with your whole command, leaving your trains to follow. It is very important that you should be here at a very early hour in the morning. A severe engagement is likely to take place, and your presence in necessary.

I am, general, very respectfully, your obedient servant,
GEORGE D. RUGGLES,

Colonel and Chief of Staff.

Under this order General Porter marched promptly with his corps toward Centreville. He had passed Manassas Junction with the head of his column, when he was halted by counter-orders, issued in consequence of a grave change which had occurred in the situation since the night before.

King had withdrawn from his position near Jackson's right, on the Warrenton turnpike, and had fallen back to Manassas Junction. Ricketts had fallen back in the night from Thoroughfare Gap to Gainesville, and thence, in consequence of the movement of King, had retired to Bristoe Station.

Thus the way had been left open for the retreat of Jackson to Thoroughfare Gap or for the advance of Longstreet from that point, and ample time had elapsed for them to effect a junction, either at the Gap or near Groveton, before a force could again to interposed to prevent it. The opportunity to attack Jackson's detached force with superior numbers had passed beyond the possibility of recall.

As soon as the withdrawal of King became known to General Pope he hastily sent a verbal message to General Porter to retrace his steps and move toward Gainesville, and soon followed this message with the following order, which was received by General Porter about 9.30 a. m.:

HEADQUARTERS ARMY OF VIRGINIA, Centreville, August 29, 1862.

Push forward with your corps and King's division, which you will take with you, upon Gainesville. I am following the enemy down the Warrenton turnpike. Be expeditions or we will lose much.

JOHN POPE,
Major-General, Commanding.