5. Major-General Sykes, Fifth Corps, will move at Walnut Run, near the railroad, and camp for the night.

6. The Reserve Artillery will move to Slater's Run, on the line of the railroad.

7. The trains will move to the vicinity of Brentsville.

8. Kilpatrick's division of cavalry will be at Buckland Mills, on the Warrenton and Centerville pikes.

9. Gregg's division will be between Warrenton and Auburn.

10. Buford's division will be at Warrenton Junction.

11. The regular brigade will be at Bristoe and Manassas.

This cavalry will picket from Bristoe around by Buckland Mills to Warrenton Junction, and to the right of the trains.

12. Corps commanders will call in teh guards with supply and baggage trains, and put every man in the ranks that can carry a musket.

Provost guards will be reduced to the smallest possible numbers.

13. Headquarters to-night at Catlett's, near the fork of the roads to Auburn and Greenwich.

By command of Major-General Meade:

S. WILLIAMS,

Assistant Adjutant-General.

(Copy to corps and independent commanders.)

HEADQUARTERS ARMY OF THE POTOMAC, October 13, 1863-1. 30 p. m. (Received 2. 15 p. m.)

Major-General HALLECK:

The infantry from General Gregg last night was so positive that the enemy-having driven him from Waterloo, Sulphur Springs, and Fox's Ford, all on my right-were crossing in heavy force, that the army was put in motion as soon as the advance at Brandy could be drawn in and is now falling back. I shall occupy to-night a line from Greenwich to Bristoe Station, and continue my retrograde movement, if possible, till I get to the plains of Manassas or across Bull Run. I cannot ascertain what progress the enemy has made, as he covers his movement by a strong cavalry force, supported by infantry and artillery. General Gregg had very severe fighting with him yesterday, and met with serious loss. I will try to advise you as long as the telegraph is working.

GEO. G. MEADE,
Major-General, Commanding.

OCTOBER 13, 1863-10 p. m. (Received 10. 35 p. m.)

Major-General HALLECK:

I have positive information that Lee's army is moving on my right, Ewell by Warrenton pike, and Hill probably by Salem. This is derived from one of Gregg's men, who was dismounted in the fight of yesterday and lay in the woods all night, and from a regiment of Gregg's command that was cut off, and in getting back passed outside of Hill's corps last night on the other side of the Rappahannock.

20 R R-VOL XXIX, PT II