Should the enemy move to prevent the operation of the cavalry or to intercept it upon its return in such force and manner as to require you to throw forward support to them, you will do so with a part or the whole of your force, as in your judgment the circumstances render necessary. It is hardly probable that the enemy can use more than 1,500 cavalry and from 8,000 to 10,000 infantry.

General Birney's division will be moved to James City on Sunday, and will communicate with you and support you upon your requiring it. Should you deem it necessary, in pursuance of the foregoing instructions, to move from Madison Court-House and that General Birney's division should move to that point or toward it, you will direct him accordingly.

You will keep the major-general commanding advised of the progress of your march, and of everything that occurs, both by signal telegraph and by courier.

A. A. HUMPHREYS,

Major-General, Chief of Staff.

An extra signal officer will be sent you.

CONFIDENTIAL.] HDQRS. ARMY OF THE POTOMAC,

February 26, 1864-8 p. m.

Major-General PLEASONTON,

Commanding Cavalry Corps:

The major-general commanding directs that you re-enforce General Kilpatrick's division so that he will have available 4,000 officers and men, besides his picket-line (supports excepted) and ordinary camp guards. The re-enforcements should be sent by such routes and at such times (reference being had to the contemplated movement) as will insure their reaching him secretly. An adequate force of cavalry will be assigned by you to General Custer for the purpose of operating in the direction of Charlottesville, in order to facilitate other operations of this army. If he should find it practicable to advance so far as to enable him to destroy the railroad bridge over the Ravine, in the vicinity of Charlottesville, he will do so, but his movements must be governed by the consideration that the infantry column upon which he can call for support, should the movements of the enemy require it, will halt at Madison Court-House, and that the enemy may be able to throw forward cavalry and infantry to interrupt his progress.

General Custer will be directed to move at such time and manner from the vicinity of Culpeper as will enable him to reach and pass through Madison Court-House unobserved by the enemy.

The cavalry will be supported in its operations by or from the column of General Sedgwick (two divisions of infantry), which will reach Madison Court-House on Sunday afternoon, the 28th instant, and take position there. After having destroyed the railroad bridge across the Ravine, or after having advanced as far as practicable consistent with the security of his return to within supporting distance of Madison Court-House, General Custer will return with his command to the vicinity of Culpeper. During the operations he will maintain constant communication with Major-General Sedgwick, commanding the column at Madison Court-House, and with these headquarters through the usual channel. In advance of his