turnpike upon Gainesville, so as to intercept any re-enforcements coming to Jackson through Thoroughfare Gap, and instructing Reno, with his command, and Kearny, with one division of Heintzelman's, to march on Greenwich, so as to support McDowell in case of necessity. With Hooker's division, of Heintzelman's corps, I moved back along the railroad upon Manassas Junction. Near Kettle Run Hooker came upon the advance of Ewell's division in the afternoon of the 27th. A severe action took place, which terminated at dark, Ewell being driven from the field with the loss of his camp and 300 killed and wounded.

The unfortunate oversight of not bringing more than 40 rounds of ammunition became at once alarming. At night-fall Hooker had but about 5 rounds to the man left. As soon as I learned this, I sent back orders to Fitz John Porter to march with his corps at 1 o'clock that night, so as to be with Hooker at daylight in the morning. The distance was only 9 miles, and he received the dispatch at 9.50 o'clock, but did not reach the ground until after 10 o'clock next morning. He can probably explain better than I can the reason of this delay. Fortunately Hooker had handled the enemy so severely the evening before and the movement of McDowell had begun to be so apparent that the enemy, fearful of being surrounded, had retired precipitately from Manassas Junction, directing his retreat through Centreville, as McDowell, Reno, and Kearny had made the road through Gainesville impracticable. I immediately pushed forward to Manassas and thence to Centreville, which was occupied by Kearny that night only a few hours after the enemy had left it. Reno had reached Manassas Junction and Fitz John Porter was immediately ordered up from Broad Run, where he had stopped. McDowell's movement, conducted with vigor and speed, had been completely successful, the enemy being intercepted at Gainesville and part of his forces driven through Thoroughfare Gap. With King's division and Sigel's corps McDowell continued his march along the turnpike toward Centreville, leaving Ricketts, with his division, in observation of Thoroughfare Gap.

Late in the evening of the 28th McDowell's advance (Gibbon's brigade) met the force of Jackson retiring from Centreville and about 6 miles west of that place. A very sharp skirmish took place, ended by the darkness, in which the brigade of Gibbon behaved very handsomely and suffered heavy loss. Sigel was close at hand with his corps, but did not join the action. I instructed Kearny to move forward at early day-dawn from Centreville toward Gainesville, closely followed by Hooker and Reno, and engage the enemy thus placed between McDowell and Sigel on the west, Heintzelman and Reno on the east, and Fitz John Porter on the south. I also instructed F. J. Porter, with his own corps and King's division of McDowell's corps - which had for some reason fallen back from the Warrenton turnpike toward Manassas Junction - to move at daylight in the morning upon Gainesville along the Manassas Gap Railroad until they communicated closely with the forces under Heintzelman and Sigel, cautioning them not to go farther than was necessary to effect this junction, as we might be obliged to retire behind Bull Run that night for subsistence, if nothing else. Heintzelman marched early from Centreville toward Gainesville, closely followed by Reno.

Meantime, shortly after daylight, Sigel, and Reynolds' division of McDowell's corps, had become engaged with the enemy, who was brought to a stand, and he was soon joined by Heintzelman and Reno, and the whole line became actively engaged. Porter marched as directed, followed by King's division, which was by this time joined by