HEADQUARTERS CAVALRY,
May 5, 1863.

Brigadier-General GIBBON,

Second Division, Second Corps:

GENERAL: Your note of this date is received. I am not authorized to detach any part of the cavalry to other commands without orders from headquarters Army of the Potomac, but I am positively ordered to obtain all the cavalry I can to carry out my instructions.

Very respectfully, your obedient servant,

A. PLEASONTON,

Brigadier-General.

PHILLIPS' HOUSE, VA.,

May 5, 1863 - 3.20 p. m.

General BUTTERFIELD:

United States Ford:

General Pleasonton clams to be here under the direct orders of General Hooker, with certain plans to carry out. Please inform me whether I am responsible for the defense of this part of the river, and whether I have command of all the troops in the vicinity.

JOHN GIBBON,

Brigadier-General.

HEADQUARTERS CAVALRY,
May 5, 1863 - 3.45 p. m.

General BUTTERFIELD, Chief of Staff:

Two brigades of rebels can be seen moving toward Hamilton's Crossing; eleven wagons following first brigade. A regiment can also be seen in rifle-pits on the ridge back of Fredericksburg. If you have pushed them to-day, this would indicate a retrograde movement. Have the rebels any means of crossing below Fredericksburg? Perhaps they have a pontoon train we know nothing of.

A. PLEASONTON,

Brigadier-General, Commanding.

HEADQUARTERS ARMY OF THE POTOMAC,
May 5, 1863 - 4.10 p. m.

General JOHN GIBBON, Phillips' House:

Your note of this date with reference to General Pleasonton's command received. I know nothing of the instructions General Pleasonton has received, but will at once refer the subject to the major-general commanding for his decision thereon.

S. WILLIAMS,

Assistant Adjutant-General.

HEADQUARTERS CHIEF ENGINEER OF DEFENSES,
Washington, May 5, 1863.

Colonel J. C. KELTON,

Assistant Adjutant-General:

SIR: I herewith transmit you a copy of a memorandum concerning the defenses of Harper's Ferry, prepared for Colonel Reynolds, engineer.