HDQRS. DEPARTMENT OF THE RAPPAHANNOCK,
May 22, 1862.

Major General GEORGE B. McCLELLAN,

Commanding Army of the Potomac, White House, Va.:

I have received the orders of the President to move with the army under my command and co-operate with yours in the reduction of Richmond, and also a copy of his instructions to you in relation to that co-operation.

Major-General Shields will join me to-day. As soon as the necessary preparations for the march can be completed, which I think will be by the 24th instant, we shall set forth in the general direction ordered. There is in front of us to impede our advance the secession army of the Rappahannock, so called, under the command of Joseph R. Anderson, of the Tredegar Iron Works. His force is from 12,000 to 15,000 men, mostly South Carolina and Georgia troops.

We should engage this force on our first day's march, as they are now within from 6 to 8 miles of us, posted on and to the right and left of the Fredericksburg and Richmond Railroad, and in a position of considerable strength. It is my purpose to try and turn their position by throwing a force on their left flank and cut off their opportunity of receiving any re-enforcements from the direction of Fordonsville, and at the same time endeavor to save the railroad bridges. If this can be done, another channel of supplies can be had for the forces going against Richmond that cannot fail giving a great relief to the quartermaster and commissary departments of your army, and thus facilitate your operations. We cannot rely on this at first, because they now occupy the line, and I am told are prepared to destroy the bridges if they are forced to fall back.

I beg to ask to what extent can I rely on co-operation from you in my present movement, in the way of your cutting off the retreat of the enemy upon Richmond, where they would add 12,000 to the forces against you, and in saving the railroad bridge across the Pamunkey, and to what point on the Pamunkey can you extend your right to join me, and to what point on the Pamunkey can you extend your right to join me, and to what point can you cause supplies to be placed for my command, and by what date can I count on finding them ready for me?

I shall require subsistence for 38,000 men and forage for 11,000 animals.

IRVIN McDOWELL,

Major-General, Commanding Department.

HDQRS. DEPARTMENT OF THE RAPPAHANNOCK,
May 22, 1862.

Hom. E. M. STANTON, Washington:

Your message to General McDowell is just received. He being absent I reply to inform you that your first message, being in cipher, was not legible by the ordinary operators. An engine and hand car could be sent from Aquia to Fredericksburg, and I know no reason why General McDowell could not be present at a conference at any hour named. I haves sent your message to him meanwhile.

ED. SCHRIVER,

Chief of Staff.