BELLE PLAIN, May 18, 1864-8 a.m.

(Received 9.35 a.m.)

WAR DEPARTMENT:

I have some ammunition on my hands here. Having no transportation to furnish the troops on their arrival here en route to the army, this surplus ammunition was left behind. I omitted in my dispatch of midnight May 17 to say that the attack by guerrillas was made at 3 p.m. yesterday. I did not receive the information until 11 o'clock last night, by Captain Nicholls whose command was attacked and his guide wounded. Mosby is dressed in our uniform.

Two hundred and fifty cavalry (Eighth Illinois) are on his track.

J. J. ABERCROMBIE,

Brigadier-General, Commanding.

WASHINGTON, May 18, 1864-10.50 a.m.

Brigadier-General ABERCROMBIE,

Belle Plain, Va.:

General Augur will immediately send cavalry re-enforcements. In the mean time use any troops that may arrive for the defense of depot and trains.

H. W. HALLECK,

Major-General and Chief of Staff.

WASHINGTON, May 18, 1864-12.15 p.m.

Brigadier-General ABERCROMBIE,

Belle Plain, Va.:

Such of the Reserve Artillery sent back by General Grant as are not required for the defense of your depot will be forwarded to Washington.

H. W. HALLECK,

Major-General and Chief of Staff.

BELLE PLAIN, May 18, 1864-8.30 p.m.

WAR DEPARTMENT:

I will have, with the cavalry coming, sufficient force. The force for Colonel Schriver has started-280 cavalry, in command of Major McIrvin; 1,850 heavy artillery, in command of Colonel Kellogg, Second Connecticut Artillery has arrived and gone forward. The Ninth New York Heavy Artillery has reported, 1,900 strong. Will hurry them on, escorting trains.

J. J. ABERCROMBIE,

Brigadier-General, Commanding.

MAY 18, 1864.

General AUGUR:

Please send immediately to Belle Plain the remainder of the Eighth Illinois Cavalry, and such of the Army of the Potomac cavalry as can be remounted.

H. W. HALLECK,

Major-General and Chief of Staff.