CONFIDENTIAL.] HEADQUARTERS ARMY OF THE POTOMAC,

July 26, 1864-8.15 p. m.

Major-General WARREN,

Commanding Fifth Army Corps:

I am instructed to inform you that General Hancock is moving his corps across the James River, and that General Sheridan, with two divisions of cavalry, is likewise moving across it. It is supposed that this movement will induce the enemy to send a considerable part of his force now in our front toward Richmond, and that an opportunity will be presented to attack him here. Should it occur, an assault will be made from Burnside's front, preceded by the springing of his mine, which is now being prepared for explosion. In such case you will be required to support Burnside's attack, concentrating your force on his left. This will require the abandonment of a part of the front you now hold. The commanding general desires you to have in view the arrangements necessary to carry out such project, and to be prepared to execute orders to that effect. The mine cannot probably be fully prepared before to-morrow night.

A. A. HUMPHREYS,

Major-General and Chief of Staff.

HEADQUARTERS ARMY OF THE POTOMAC, July 27, 1864-9.30 a. m.

Major-General WARREN:

I think it extremely probable the effect of Hancock's movement may produce an attempt on the part of the enemy to turn and attack our left flank. I therefore desire you will keep in view the contingency of holding your intrenchments with the minimum force, and being prepared to send any available movable force to the left and rear.

GEO. G. MEADE,
Major-General.

HEADQUARTERS ARMY OF THE POTOMAC, July 27, 1864.

Major-General WARREN:

A report from General McIntosh, commanding cavalry on our left, announces the enemy's infantry in force on the plank road abreast of Lee's Mill, and the running of trains all night. My inference is that the disappearance of Hancock's corps has been mistaken for a raid on the Weldon railroad, and troops have been thrown to meet [it]. I now expect, when the real position of Hancock is known, they will try our left and rear. I have ordered Burnside to send two brigades to occupy the works vacated on your left by Hancock.

GEO. G. MEADE,

Major-General.

HEADQUARTERS FIFTH ARMY CORPS, July 27, 1864-10 a. m.

Major-General MEADE:

I have received your dispatch in relation to our left. The preparations for the contingency you mention, and for the opposite one mentioned by General Humphreys last night, require nearly the same preliminary preparations. I will send by an orderly a report on my arrangements.

Respectfully,
G. K. WARREN,

Major-General of Volunteers.