HARRISBURG, PA, September 6, 1862.

(Received 11.20 p. M.)

Honorable EDWIN M. STANTON,

Secretary of War:

The following has just been received from a messenger I sent out last night:

HAGERSTOWN, 6TH.

Governor A. G. CURTIN:

Parties who left Frederick City at 4 o'clock this afternoon, who have just arrived, say that 6,000 rebels arrived to-day there. Report main body on the way to Baltimore. Our troops still at Martinsburg, General White commanding. Only these companies Pennsylvania Twenty-ninth here. People greatly alarmed here; 14,000 Federals at Harper's Ferry. General White must be re-enforced heavily at Martinsburg or fall back to Williamsport. If not, his whole command will be captured. Troops in large numbers necessary in Cumberland Valley.

A. G. CURTIN.

[19.]

HEADQUARTERS ARMY OF THE POTOMAC,
September 6, 1862-5.20 p. M.

Major General F. J. PORTER,

Commanding Fifth Corps:

General McClellan directs me to say that Generals McDowell's and Franlin's corps have been ordered to this side of the river. You will relieve them with your command. The charge of all the forts from De Kalb to Hunting Creek are intrusted to you. Please have all the heavy guns withdrawn from Upton's Hill and vicinity to-night. That position will be held by an advance guard of infantry and artillery, which can retire on the appearance of the enemy in force. General Sigel will hold the forts at the Chain Bridge and connect with you. The division under General Sturgis will be at once concentrated and ordered to report to you. The line of works must be held by the force that can be left with you. Every man that can possibly be withdrawn is required on this side.

A. V. COLBURN,

Assistant Adjutant-General.

[19.]

HEADQUARTERS,
Washington, September 6, 1862-6.40 p. M.

Major-General PORTER,

Hall's Hill:

The general commanding desires that General Sykes place his division in motion immediately and proceed to Tennallytown or vicinity and there encamp. General Sykes will report in person to the general commanding this evening after having taken all the steps necessary for the prompt movment of his division. Sykes' division will for the present move with the headquarters, reporting directly to the general commanding, and will constitute a reserve under the personal orders of the general. It will encamp with headquarters. The batteries of General Sykes move with him. Please acknowledge.

S. WILLIAMS,

Assistant Adjutant-General.

[19.]