Maryland Heights, Md., June 21, 1863.

(Copy received, War Department, 5. 20 p. m.)

Major-General HOOKER:

Since I arrived here, I have obtained information differing from what I gave you yesterday, viz: That the rebels during yesterday advanced in considerable force, and late last evening occupied about the same position that they did prior to the battle of Antietam - that is, they were occupying the old battle-ground. The were seemingly drawn up in line of battle the whole of yesterday afternoon. The above was received from a whole-souled Union man.

DAN. TYLER,

Brigadier-General.

Headquarters FIFTH CORPS, June 21, 1863-8 p. m.

General O. O. HOWARD:

General Pleasonton, with all the cavalry and his batteries, supported by a division and battery of this corps, advanced this morning from Middleburg, on the Ashby's Gap road, driving slowly the enemy's cavalry and artillery. I send you the only two dispatches I have received from the front, giving you all the information I have. Can you send it to Reynolds? Yours,

MEADE.

[Enclosures.]

June 21, 1863-12. 30 p. m.

I have the honor to report our cavalry driving the enemy toward Ashby's Gap. They have driven them about 2 miles. Colonel Vincent's brigade is on the left, supporting two batteries, the remaining two in reserve. There is no appearance of any infantry force between here and the Blue Ridge. I remain, yours, very respectfully,

JAMES C. BIDDLE,

Major, and Aide-de-Camp.

4. 30 P. M.

Major-General MEADE, Commanding Corps: We have driven the rebels to Upperville, and are still driving them. Have seen no indications of infantry thus far. The Second Brigade has relieved the First. I remain, yours, &c.,

JAMES C. BIDDLE,

Major, and Aide-de-Camp.

[P. S] - We captured one Blakely gun and exploded two of their caissons.

MONOCACY JUNCTION, MD., June 21, 1863.

(Copy received, War Department, 8 p. m.)

Colonel G. H. SHARPE,

Deputy Provost-Marshal, Army of the Potomac:

At 4 p. m 40 of the First Maryland Cavalry routed the enemy in Frederick, leaving soon after. A force of 150 rebel cavalry imme-