JULY 6, 1863.

Colonel L. B. PIERCE, Mercersburg, Pa.:

Gregg at Fayetteville this evening, driving the enemy. You have already done nobly. Now co-operate with Gregg, and get your share of the prisoners.

By order of Major-General Couch:

WAYNE McVEAGH,

Major, and Aide-de-Camp

LOUDON, July 6, 1863-11 p. m.

Major-General COUCH:

Your dispatch just received. Fitzhugh Lee, with 2, 000 cavalry, some artillery, said to be within 10 miles of me, in the direction of Mercersburg, marching for this place. Have sent my prisoners and wagons into pass in mountain. Expect I will have to attend to him before morning. Will help Gregg as soon as I can.

L. B. PIERCE,

Colonel, Commanding.

MERCERSBURG, July 6, 1863.

General COUCH, Harrisburg:

I learn direct from Millstone Point that the rebels are retreating in great haste, with a large force of cavalry to guard their train. Just as soon as I can secure what I have now got, will pitch into them again. Eighty-three prisoners taken and paroled at Chambersburg last night by First New York Cavalry, under Major A. W. Adams. He reports General Jenkins, with a large body of cavalry, seen 3 1/2 mile from Chambersburg, on Greencastle road. He drove in their pickets, and went in sight of their camp.

L. B. PIERCE,

Colonel, Commanding.

HARRISBURG, PA., July 6, 1863. (Received 9. 35 p. m.)

H. W. HALLECK,

General-in-Chief:

Gregg was at Fayetteville at 6 p. m., driving rebels, and capturing 4, 000 prisoners.

D. N. COUCH,

Major-General.

NAVY DEPARTMENT, July 6, 1863.

Acting Rear-Admiral S. P. LEE,

U. S. NAVY, Commanding N. A. B. Squadron, Old Point Comfort, Va.:

On the arrival of the Mahaska and other gunboats, you are authorized to make such a demonstration up the James River as in your judgment would be advisable, in view of the desire of the Govern-