The general directs that the Eleventh Corps cross to the opposite side of the river to-night, and that the Twelfth Corps commence crossing at daylight to-morrow morning, and to be thrown over with all possible rapidity, and both corps march by the most direct route, without delay, and seize the bridge, if standing, and the ford at Germanna Mills. He suggests that you make use of cavalry regiment and three or four smart marching regiments to execute this duty, and that you cross both of your corps over the Rapidan River to-morrow. You will find guides in General Pleasonton's cavalry.

Major-General Meade will move on almost a parallel line at the same time, and will be in easy communication with you. He will cross at Ely's Ford. If his passage should be disputed, as you will probably be able to learn from the firing, or through your communication with that officer, the general directs that you dispatch a corps along the south bank of the Rapidan, to knock away the enemy, to enable him to cross, and, when the Fifth Corps is across, that you push on with both of your corps to Chancellorsville, at which point the three corps will come together, and which you will command by virtue of your seniority.

The enemy have a brigade holding the United States Ford, which they will abandon as soon as they hear of your approach. This will open the United States Ford to us, when bridges will at once be thrown across the river, and will afford you a direct communication with headquarters. Telegraphic communication is established from that point.

If your cavalry is well advanced from Chancellorsville, you will be able to ascertain whether or not the enemy is detaching forces from behind Fredericksburg to resist your advance. If not in any considerable force, the general desires that you will endeavor to advance at all hazards, securing a position on the Plank road and uncovering Banks' Ford, which is also defended by a brigade of the rebel infantry and a battery. If the enemy should be greatly re-enforced, you will then select a strong position, and compel him to attack you on your ground. You will have nearly 40,000 men, which is more than he can spare to send against you. Every incident of your advance you will communicate to the general as soon as communication is established by the United States Ford. Two aides-de-camp are sent to report to you for this service. You are already advised of the operations going on below Fredericksburg.

The general desires that not a moment be lost until our troops are established at or near Chancellorsville. From that moment all will be ours. A copy of this will be furnished Major-General Meade.

It will be much easier to replenish batteries, ammunition, &c., by Banks' Ford than by the United States Ford, if you should succeed in uncovering it.

Very respectfully, your obedient servant,

WM. L. CANDLER,

Captain and Aide-de-Camp.

HEADQUARTERS ARMY OF THE POTOMAC,
Morrisville, Va., April 28, 1863.

Brigadier General A. PLEASONTON,

Commanding Cavalry:

I am directed by the major-general commanding to instruct you to report with your command of cavalry to Major-General Slocum, for service with his command. A portion of your force will accompany his command, and a portion will be sent to report for duty with the Fifth