the Confederate general, Jackson, with three divisions of infantry, one of cavalry, and some artillery, commenced his movement to turn the Union right through Thoroughfare Gap, which Gap he passed on the 26th, and that night struck the rear of the Union army at Bristoe and Manassas Junction. The next morning, August 27, the Union army changed front to the rear, and was ordered to move on Gainesville, Greenwich, and Warrenton Junction.

General Porter, with his two divisions of the Fifth Corps, arrived at Warrenton Junction on the 27th, and there reported in person to General Pope. That afternoon Hooker's division was engaged with the enemy at Bristoe Station; McDowell and Sigel were moving on Gainesville, and Heintzelman and Reno on Greenwich. Banks was covering the rear below Warrenton Junction and guarding the trains in their movement toward Manassas Junction. Porter was at first ordered to move toward Greenwich upon the arrival of Banks at Warrenton Junction, but after Hooker's engagement at Bristoe the following order was sent him, and he received it at 9.50 p. m.:

HEADQUARTERS ARMY OF VIRGINIA, Bristoe Station, August 27, 1862-6.30 p. m.

Major General F. J. PORTER, Warrenton Junction:

GENERAL: The major-general commanding directs that you start at 1 o'clock to-night and come forward with your whole corps, or such part of it as is with you, so as to be here by daylight to-morrow morning. Hooker has had a very severe action with the enemy, with a loss of about 300 killed and wounded. The enemy has been driven back, but is retiring along the railroad. We must drive him from Manassas, and clear the country between that place and Gainesville, where McDowell is. If Morell has not joined you, send him word to push forward immediately; also send word to Banks to hurry forward with all speed to take your place at Warrenton Junction. It is necessary on all accounts that you should be here by daylight. I send an officer with this dispatch who will conduct you to this place. Be sure to send word to Banks, who is on the road from Fayetteville, probably in the direction of Bealeton. Say to Banks, also, that he had best run back the railroad trains to this side of Cedar Run. If he is not with you, write him to that effect.

By command of General Pope:

GEORGE D. RUGGLES,
Colonel and Chief of Staff.

P. S.-If Banks is not at Warrenton Junction, leave a regiment of infantry and two pieces of artillery as a guard till he comes up, with instructions to follow you immediately upon his doing so. If Banks is not at the Junction, instruct Colonel Clary to run the trains back to this side of Cedar Run, and post a regiment and a section of artillery with it.

By command of General Pope:

GEORGE D. RUGGLES,

Colonel and Chief of Staff.

This order plainly contemplated an aggressive movement against the enemy early on the 28th, and required the presence of General Porter's corps at Bristoe Station as early as possible in the morning, to take part in the pursuit of and attack upon the enemy.

The order did not indicate any anticipation of defensive action at Bristoe, but, on the contrary, it indicated continuous, active, and aggressive operations during the entire day of the 28th, to drive the enemy from Manassas and clear the country. Hence the troops must arrive at Bristoe in condition for such service.

The evidence clearly shows that General Porter evinced an earnest desire to comply literally with the terms of the order, and that he held a consultation with his division commanders, some of his brigade commanders, and his staff officers on the subject. One of his divisions had arrived in camp late in the evening, after a long march, and was much fatigued.