HEADQUARTERS ARMY OF THE POTOMAC, August 4, 1864-1 p. m.

Brigadier-General GREGG,
Commanding Cavalry Corps:

The major-general commanding has received instructions from the lieutenant-general commanding the armies in the field to send another cavalry division to Washington. The major-general commanding is at General Butler's headquarters, where I have telegraphed him. In the meantime make every preparation for moving to City Point for embark-action that division of cavalry which can be most quickly got there, consideration also being given to its effectiveness-that is, it must be in condition for rapid movement after reaching Washington. The artillery and means of transportation of the division will also go to City Point, but will not be embarked until the troops are embarked. General Kautz is directed to remain on duty with this army. Inform me in reply what division will go. In the event of your division going you will accompany it, and will turn over to General Wilson all orders respecting the disposition of the cavalry. One division will be posted on the left and rear as far as the Blackwater, and the remaining division between the Blackwater and James. As far as practicable, what force is not needed for patrols and pickets will be kept concerntrated ready for movement against the enemy. If any modifications of this should be thought necessary the commander of the cavalry will please suggest them.

A. A. HUMPHREYS,

Major-General and Chief of Staff.

HDQRS. CAVALRY CORPS, ARMY OF THE POTOMAC, August 4, 1864.

Major General A. A. HUMPHREYS,
Chief of Staff, Army of the Potomac:

GENERAL: I have the honor to designate the Second Division (that commanded by myself) as the division to proceed to Washington. The brigades of the division are posted at Prince George Court-House and on the Norfolk railroad, and can most conveniently be moved to City Point for shipment.

I am, very respectfully, your obedient servant,

D. McM. GREGG,

Brigadier-General of Volunteers, Commanding Cavalry Corps.

HEADQUARTERS ARMY OF THE POTOMAC, August 4, 1864-3.20 p. m.

COMMANDING OFFICER CAVALRY CORPS:

The major-general commanding directs that you send Wilson's division to City Point for embarkation. Instructions for picketing the left of the army same as already sent you. Kautz's division will remain with you.

A. A. HUMPHREYS,
Major-General and Chief of Staff.