HEADQUARTERS ARMY OF THE POTOMAC,
April 17, 1863-9 a. m.

His Excellency the PRESIDENT OF THE UNITED STATES:

Mr. PRESIDENT: I have the honor to acknowledge your communication of the night of the 15th instant, and, ion compliance with your request, transmit herewith a letter from General Stoneman, dated the 16th instant, as it will fully inform you of the circumstances, attending his march up the river and also of his present position. The letter was this moment received.

His failure to accomplish speedily the objects of his expedition is a source of deep regret to me, but I can find nothing in his conduct of it requiring my animadversion or censure. We cannot control the elements.

From your letter, I conclude that you had misapprehended the position of his advance the night of the second day out from here, which was on the south side of the Rappahannock, and 50 miles from this camp. His own dispatch was dated Bealeton, in the vicinity of his rear guard. I have given directions for him to remain in his present position, holding himself in readiness to march as soon after the roads and rivers will permit as practicable, at the shortest notice, and I still hope to turn his moment to some good account. I do not regard him out of position, as, in case of an advance of so large an army, it would be necessary to throw the main portion of his force well on to my right flank. It would take until doomsday to pass all this army over one or two lines. He has a week's supplies on hand, and, if it should become necessary to replenish, it be done as readily at Rappahannock Station as at Falmouth. I have sent learn the condition of the Orange and Alexandria Railroad.

No one, Mr. President, can be more anxious that myself to relieve your cares and anxieties, and you may be assured that I shall spare no labor and suffer no opportunity to pass unimproved for so doing.

We have no reason to suppose that the enemy have any knowledge of the design of General Stoneman's movement.

I have the honor to be, very respectfully, your most obedient servant,

JOSEPH HOOKER,

Major-General.

[Inclosure.]

HDQRS. CAVALRY CORPS, ARMY OF THE POTOMAC,
Camp near Rappahannock Railroad Bridge, Va., April 16, 1863.

Brigadier General S. WILLIAMS,

Assistant Adjutant-General, Army of the Potomac:

GENERAL: Your letter of April 15, 1863, was received at 12 m. to-day, and I have delayed answering it until this hour, awaiting the acknowledgment of my two dispatches of yesterday, which has this moment come to hand. I cannot say what has been the state of affairs away from this vicinity, but here, at the hour of my last dispatch, the condition of things may be judged of when I tell that almost every rivulet was swimming, and the roads next to impassable for horses or pack-mules, not speak of artillery and wagons, the latter of which had in the morning all been started for the rear. The railroad bridge has been partly carried away by the freshest. The river is out of its banks, and was still on the rise a few hours ago. There hours ago Gregg's division, which was directed to move back from the river to higher ground, began crossing a bed nearly dry yesterday morning, and