HEADQUARTERS ARMY OF THE POTOMAC,
April 23, 1864.

Major-General SHERIDAN,

Commanding Cavalry Corps:

The major-general commanding directs that you strengthen the detachment at Grove Church by such force as you deem necessary; that General Gregg be directed to hold his division in readiness to move at a moment's notice, and that a portion of General Wilson's division, not less than a brigade, be held ready to move and unite with Gregg, or act in conjunction with him by crossing at lower fords of the Rappahannock (Ellis' Ford).

A. A. HUMPHREYS,

Major-General, Chief of Staff.

HDQRS. CAVALRY CORPS, ARMY OF THE POTOMAC,
April 23, 1864.

General GREGG,

Commanding Second Cavalry Division:

GENERAL: Inclosed you will find a note from General Humphreys in reference to the enemy's cavalry. Instruct the regiment at Morrisville to push scouts well out toward Tackett's Mills, and keep a bright lookout yourself. I do not think they intend to cross. They are covering that flank, perhaps, in anticipation of some general movement of ours.

Yours, truly,

P. H. SHERIDAN,

Major-General, Commanding.

[Inclosure.]

HEADQUARTERS ARMY OF THE POTOMAC,
April 23, 1864.

Major-General SHERIDAN,

Commanding Cavalry Corps:

I do not know whether the major-general commanding informed you this morning that information reached him last night that the enemy were concentrating all their cavalry at Hamilton's Crossing. Hamilton's Crossing is a few miles south of Fredericksburg, at the railroad crossing of the Massaponax River.

A. A. HUMPHREYS,

Major-General, Chief of Staff.

PICKET RESERVE,

Near Grove Church, April 23, 1864.

Major-General SHERIDAN,

Commanding Cavalry Corps:

A deserter from Thirteenth Virginia Cavalry arrived. Reports all of Stuart's cavalry at Fredericksburg. Strength of this post known. Intend to surprise it some night.

O. HARHAUS,

Colonel, Commanding 2nd N. Y. Cav., Commanding Picket Post.