[Sub-inclosure No. 3.]

HEADQUARTERS ARMY OF THE POTOMAC, January 20, 1863-10.45 p.m.

Major-General HOOKER,
Commanding Center Grand Division:

GENERAL: In addition to the orders already give you, the following will be for your guidance, if you succeed in crossing your command at the designated place: You will, if possible, seize the heights upon which Decker's house is situated, occupying at the same time the wooded ground above it. The bridge over Mott Run, near the foot of Decker's Hill, should be secured as early as possible, and held either under the guns of the battery or by an infantry force. You will readily see the importance of securing this bridge, as it will be the only rapid means of communication between yourself and General Franklin. These two points having been occupied, you will extend your command as much to the right and front as possible, keeping your advanced line well supported. The Plank road is some 2 1/2 miles from Decker's house, and it is very desirable to secure a position on that road at or in advance of Salem Church, which is about three-quarters of a mile from the intersection of the Fall Hill road with the Plank road. The Fall Hill road is the one that runs up the river from Fredericksburg until it reaches a point opposite Falmouth, when it bears to the left, and, passing Dr. Taylor's house, intersects the Plank road at Morrison's. General Franklin is ordered, after crossing, to secure the heights above his crossing, and afterward Taylor's Heights, and, in case he is successful, to extend his right to the neighborhood of Guest's house. You will please hold yourself in readiness to support his right, and, in case the enemy should vacate the heights in his front, it may be advisable to throw your force down the old Mine road to the Telegraph road. This road is wrongly laid down on the map; it is nearer Fredericksburg than the map represents. It may be well to state that there is an infantry and cavalry force in the vicinity of the United States Ford that needs watching. I have attached to General Averell another regiment, 1,000 strong, and have relieved a portion of his pickets. He is subject to your order, having simply received orders from me to remain at Potomac Creek, ready to move at a moment's notice, when ordered by you or myself. It having been reported by Captain Comstock that the crossing below General Franklin's, ordered for General Sumner's command, is impracticable, I have ordered General Sumner to hold his two corps in readiness to follow you and General Franklin. I shall, however, attempt to throw a bridge at that place for footmen, at least.

These instructions may be materially modified by the events of tomorrow, during which day I hope to be in frequent personal communication with you. I need not say to you that this attack upon the enemy should be a vigorous one. My headquarters will be at Wroton's house until 8 a.m. An aide will be sent to communicate with you. I will send you a guide before you commence your movement across the river tomorrow morning.

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

A. E. BURNSIDE,

Major-General, Commanding.

[Inclosure No. 27.]

HDQRS. ARMY OF THE POTOMAC, January 20, 1863.

Colonel A. BUSCHBECK,

Commanding:

You will make the following disposition of the troops in your division: One brigade to take position at once in support of the batteries on the