HEADQUARTERS CAVALRY BRIGADE,
Yorktown, Va., January 27, 1864.

Colonel B. F. ONDERDONK,

Commanding First New York Mounted Rifles:

COLONEL: For the purpose of carrying out the intent of General Orders, Numbers 1, current series, headquarters Yorktown, Va., you will proceed to enroll all citizens, both white and colored, residing within that district of country lying between the York and James Rivers north and west of a line commencing at the mouth of the Back River (upper branch); thence to its head across to the head of Deep Creek, and thence to its mouth inside of and within 3 miles of the picket-line in front of Williamsburg.

You will detail a force, to consist of not less than two strong companies, to proceed at once to the line above indicated, there to commence upon the duty prescribed, coming in the direction of Williamsburg, and proceeding until the duty assigned shall have been accomplished; they will carry sufficient rations of forage and subsistence to enable them to fully accomplish the purpose intended, viz, a full and complete enrollment.

Should it seem more feasible or advisable you can at your discretion divide the district assigned you into sub-districts, taking care that a sufficient number of men be allotted to each district to fully carry out the object of general orders.

I send a list of citizens already enrolled, which may be of use; be pleased to return it as soon as you shall have finished with it.

I write by command of Colonel S. P. Spear.

I am, sir, very respectfully, your obedient servant,

C. HAMILTON SHEPARD,

Lieutenant and Acting Assistant Adjutant-General.

HEADQUARTERS ARMY OF THE POTOMAC,
January 28, 1864.

General NEWTON:

In answer to your dispatch of this day's date, I am instructed to reply that the major-general commanding does not object to the withdrawal of the brigade at Cedar Mountain, but considers that the bridge at Mitchell's Station should be maintained at that point. The guard at the signal station on Cedar Mountain should erect a block-house or stockade to guard against a sudden attack.

A. A. HUMPHREYS,

Major-General, Chief of Staff.

HEADQUARTERS ARMY OF THE POTOMAC,
January 28, 1864.

General S. WILLIAMS,

Assistant Adjutant-General, Army of the Potomac:

The commanding general has directed me to erect two block-houses, one at Warrenton Junction, the other near Catlett's Station. A detail of 250 men and twenty-five wagons will be required at each of these points; half of the men in each party should be provided with axes. Captain Turnbull will be at Catlett's Station to-morrow to receive the working party.

Very respectfully,

J. C. DUANE,

Major of Engineers.