place will throw us back six months, if it should not destroy us. Beware of the evils I now point out to you. You saw them when here, but you seem to forget them in the distance. No more troops can be sent from here till we have fresh arrivals from the North.

H. W. HALLECK,

General-in-Chief.

HEADQUARTERS, Frederick, September 13, 1862-12 m.

(Received 2.35 a. m., September 14.)

To the PRESIDENT:

I have the whole rebel force in front of me, but am confident, and no time shall be lost. I have a difficult task to perform, but with God's blessing will accomplish it. I think Lee has made a gross mistake, and that he will be severely punished for it. The army is in motion as rapidly as possible. I hope for a great success if the plans of the rebels remain unchanged. We have possession of Catoctin. I have all the plans of the rebels, and will catch them in their own trap if my men are equal to the emergency. I now feel that I can count on them as of old. All forces of Pennsylvania should be placed to co-operate at Chambersburg. My respects to Mrs. Lincoln. Received most enthusiastically by the ladies. Will send you trophies. All well, and with God's blessing will accomplish it.

GEO. B. McCLELLAN.

FREDERICK CITY, MD., September 13, 1862-11 p. m.

(Received 1 p. m., September 14.)

Major General H. W. HALLECK,

General-in-Chief:

An order from General R. E. Lee, addressed to General D. H. Hill, which has accidentally come into my hands this evening-the authenticity of which is unquestionable-discloses some of the plans of the enemy, and shows most conclusively that the main rebel army is now before us, including Longstreet's, Jackson's, the two Hills', McLaws', Walker's, R. H. Anderson's, and Hood's commands. That army was ordered to march on the 10th, and to attack and capture our forces at Harper's Ferry and Martinsburg yesterday, by surrounding them with such a heavy forces that they conceived it impossible they could escape. They were also ordered to take possession of the Baltimore and Ohio Railroad; afterward to concentrate again at Boonsborough or Hagerstown. That this was the plan of campaign on the 9th is confirmed by the fact that heavy firing has been heard in the direction of Harper's Ferry this afternoon, and the columns took the roads specified in the order. It may, therefore, in my judgment, be regarded as certain that this rebel army, which I have good reasons for believing amounts to 120,000 men or more, and know to be commanded by Lee in person, in friends here that they were going to Harrisburg and Philadelphia. My advance has pushed forward to-day, and overtaken the enemy on the Middletown and Harper's Ferry roads, and several slight engagements have taken place, in which our troops have driven the enemy from their position. A train of wagons, about three-quarters of a mile long, was destroyed to-day by the rebels in their flight. We took over 50 prisoners. This army marches forward early to-morrow morning, and will make forced marches, to endeavor to relieve Colonel Miles, but I fear,