WASHINGTON, May 15, 1864-8.30 p.m.

Lieutenant-General GRANT,

Army of the Potomac, in the Field:

General Butler says that General Kautz was sent on the 12th,with orders to cut the Danville railroad, and also the James River Canal. General Augur estimates that the re-enforcements which will be at Belle Plain by to-morrow night for the Army of the Potomac will be at least 24,000. I hope in a few days to increase the number to 30,000.

H. W. HALLECK,

Major-General and Chief of Staff.

MAY 15, 1864.

General GRANT:

Burnside has been advised that Birney is under his orders and to remain there so long as in his judgment the security of his line requires it, but that so soon as he can dispense with him he is to be sent back. I fancy it is only the enemy's cavalry feeling our position.

GEO. G. MEADE,

Major-General.

HEADQUARTERS OF THE ARMY,
Near Spotsylvania Court-House, Va., May 15, 1864.

Major-General MEADE,

Commanding Army of the Potomac:

GENERAL: I have written to the commander at Fredericksburg and also to General Ferrero, commanding division of colored troops, putting them on their guard about Hampton's cavalry. We now have a large force between here and Fredericks which, if it does its duty, can prevent any serious disaster of our trains. General Burnside just now informs me that the enemy are moving on his right in considerable force, but he does not know, yet in what force or for what object. If they move on him the best possible relief will be to move the whole Army of the Potomac forward from Wright's and Warren's front.

U. S. GRANT,

Lieutenant-General.

HEADQUARTERS ARMY OF THE POTOMAC,
May 15, 1864-3.30 p. m.

[General GRANT:]

GENERAL: Your note in reference to Burnside's right being threatened is received. Warren and Wright have been ordered to be prepared to advance on the receipt of orders, and Hancock has been directed to hold his command (Birney excluded) ready to move at a moment's notice.

Respectfully, yours,

GEO. G. MEADE,

Major-General, Commanding Army of the Potomac.