HEADQUARTERS ARMY OF THE POTOMAC,
March 18, 1864-11 p. m.

Major General A. PLEASONTON,

Commanding Cavalry Corps:

GENERAL: Brigadier-General Merritt's note of 7 p. m. this evening, herewith, has been laid before the major-general commanding, who approves the plan therein proposed of establishing a signal station on Thoroughfare Mountain. A signal officer has been ordered to report to general Merritt early to-morrow morning. the commanding general directs that General Merritt throw a force well to the west, so as to ascertain if possible the signification of the large fires alluded to by him. It is of the highest importance that the commanding general should have timely notice of any movements of the enemy on the flanks of the army.

I am, very respectfully, your obedient servant,

S. WILLIAMS,

Assistant Adjutant-General.

HEADQUARTERS ARMY OF THE POTOMAC,
March 18, 1864.

Major-General PLEASONTON,

Cavalry Corps:

The commanding general desires to see you at his headquarters as soon as practicable.

S. WILLIAMS,

Brigadier-General and Assistant Adjutant-General.

HEADQUARTERS FIRST CAVALRY DIVISION,
Culpeper, March 18, 1864.

Captain F. C. NEWHALL,

Acting Assistant Adjutant-General, Cavalry Corps:

Colonel Gibbs report contrabands coming into infantry lines, who say the rebels are preparing for a raid with the intent to demonstrate on our right flank, while Stuart crosses the river below on the left flank of the army. General Ewell's corps has furnished a number of picked infantry to move with Stuart toward Fredericksburg. Lee was at Charlottesville night before last (Wednesday). Similar information was forwarded by General Newton to army headquarters.

W. MERRITT,

Brigadier-General.

HEADQUARTERS CAVALRY CORPS,
March 18, 1864-11. 45 p. m.

Brigadier-General MERRITT,

Commanding first Cavalry Division:

The major-general commanding approves the plan propose of establishing a signal station on Thoroughfare Mountain. A signal officer has been ordered to report to you early in the morning. The general commanding directs that you throw a force well out to ascer-