moment they arrive in that city. He desires that you hold your command in readiness to march at all times. He will retain as much of your command under your immediate charge as practicable. It will, however, be necessary to call upon you for regiments to serve at corps headquarters, while holding advanced positions like those of the Second and Twelfth Corps, at this time. In his opinion, they can nowhere render this army more service. Major-General Stahel's whole command is ordered to cross into Maryland to-day. Yours, therefore, is the only cavalry with the Army of the Potomac proper. Colonel Duffie has been made a brigadier-general, and it is the present intention of the general to assign him to duty with General Stahel. His regimen, as soon as in readiness, will return to you. Should you learn of any other of your command still absent, send orders for them to report to you at once. I am further directed to state that the general is of the opinion that you very much overestimate the strength of the rebel cavalry in your front, though, no doubt, his largest force is there. He had at the beginning but 12, 000, and his losses certainly cannot have been less than your own. Of this, a heavy force is in Maryland, Hampton's brigade on the Rappahannock, and lesser forces scouting everywhere. The general desires me to inquire if anything can be done with he rebel cavalry in your front by detaching an infantry force, either from the Second or the Twelfth Corps, and cutting their line of retreat. Will it be possible to find any one in your vicinity to cross the Blue Ridge and look into the Valley of the Shenandoah? By avoiding the traveled roads, it seems this service ought to be rendered with impunity. It is also of importance to know whether infantry cannot cross those mountains excepting through the gaps. Very respectfully, &c.,

S. WILLIAMS,

Assistant Adjutant-General.

LEESBURG, June 24, 1863-6 p. m.

General JOSEPH HOOKER:

Howard's corps is at the mouth of Goose Creek, and on the south side. I think he should cross the creek and take position. He can afford me but little assistance where he now is, and, if he was on this side the creek, he could be thrown across the Potomac more readily than from his present position. There is a very strong position for his entire corps on this side the creek.

H. W. SLOCUM,

Major-General.

HEADQUARTERS CAVALRY CORPS, June 24, 1863-6. 30 p. m.

Brigadier-General WILLIAMS,

Assistant Adjutant-General:

SIR: Your dispatch of this date received. A regiment has been detailed for General Slocum, and must be with him by this time. I have sent a reconnaissance to examine the country in the vicinity of Hamilton. I have also scouts out, trying to get into the Shenan-