Rebellion Record: a Diary of American Events: Documents and Narratives, Volume 5.
Frank Moore, Ed.

As soon as I discovered that a large force of the enemy was turning our right toward Manassas, and that the division I had ordered to take post there two days before, had not yet arrived from Alexandria, I immediately broke up my camp at Warrenton Junction and Warrenton and marched rapidly back in three columns. I directed McDowell, with his own and Sigel's corps, to march upon Gainesville by the Warrenton and Alexandria pike; Reno and one division of Heintzelman to march on Greenwich, and, with Porter's corps and Hooker's division, I marched back to Manassas Junction.

McDowell was ordered to interpose between the forces of the enemy which had passed down to Manassas through Gainesville, and his main body moving down from White Plains through Thoroughfare Gap. This was completely accomplished, Longstreet, who had passed through the Gap, being driven back to the west side. The forces to Greenwich were designed to support McDowell in case he met too large a force of the enemy. The division of Hooker marching toward Manassas, came upon the enemy near Kettle Run in the afternoon of the twenty-seventh, and after a sharp action, routed them completely, killing and wounding three hundred, capturing camps [604] and baggage, and many stand of arms. This morning the command pushed rapidly to Manassas Junction, which Jackson had evacuated after three hours in advance. He retreated by Centreville and took the turnpike towards Warrenton. He was met six miles west of Centreville by McDowell and Sigel, late this afternoon. A severe fight took place, which has terminated by darkness. The enemy was driven back at all points, and thus the affair rests.

Heintzelman's corp will move on him at daylight from Centreville, and I do not see how the enemy is to escape without heavy loss. We have captured one thousand prisoners, many arms, and one piece of artillery.