The president informed me that he had reason to believe that the Army of the Potomac was not cheerfully co-operating with and supporting General Pope; that he had "always been a friend of mine," and ;now asked me, as a special favor, to use my influence in correcting this state of things. I replied, substantially, that I was confident that he was misinformed; that I was sure, whatever estimate the Army of the Potomac might entertain of General Pope, that they would obey his orders, support him to the fullest extent, and do their whole duty. The president, who was much moved, asked me to telegraph to " Fitz John Porter or some other of my friends, " and try to do away with any feeling that might exist, adding that I could rectify the evil and that no one else could.

I thereupon told him that I would cheerfully telegraph to General Porter, or do ;anything else in my power to gratify his wishes and relieve his anxiety; upon which he thanked me very warmly, assured me that he could never forget my action in the matter, &c., and left.

I then wrote the following telegram to General Porter, which was sent to him by the General-in-Chief:

WASHINGTON, September 1, 1862.

Major-General PORTER:

I ask of you, for my sake, that of the country, and the old Army of the Potomac, that you and all my friends will lend the fullest and most cordial co-operation to General Pope in all the operations now going on. The destinies of our country, the honor of our arms, are at stake, and all depends now upon the cheerful co-operation of all in the field. This week is the crisis of our fate. Say the same thing to my friends in the Army of the Potomac, and that the last request I have to make of them is that for their country's sake they will extend to General Pope the same support they ever have to me.

I am in charge of the defenses of Washington, and am doing all I can to render your retreat safe should that become necessary.

GEO. B. McCLELLAN.

To which he sent the following reply:

FAIRFAX COURT-HOUSE,

September 2, 1862-10 a. m.

GENERAL GEORGE B. McCLELLAN,

Major-General, Commanding, Washington:

You may rest assured that all your friends, as well as every lover of his country, will ever give, as they have given, to General Pope their cordial co-operation and constant support in the execution of all orders and plans. Our killed, wounded, and enfeebled troops attest our devoted duty.

F. J. PORTER.

Neither at the time I wrote the telegram nor at any other time did I think for one moment that General Porter had been or would be in any manner derelict in the performance of his duty to the nation and its cause. Such an impression never entered my mind. The dispatch in question was written purely at the request of the President.

On the morning of the 2nd the President and General Halleck came to my house, when the President informed me that Colonel Kelton had returned from the front; that our affairs were in a bad condition; that the army was in full retreat upon the defenses of Washington; the roads filled with stragglers, &c. He instructed me to take steps at once to stop and collect the stragglers, to place the works in a proper state of defense, and to go out to meet and take command of the army when it approached the vicinity of the works; then to place the troops in the best position-committing everything to my hands.