HEADQUARTERS ARMY OF THE POTOMAC,
Keedysville [Md.], September 19, 1862.

Major General FITZ JOHN PORTER:

GENERAL: General Sumner reports that the enemy's artillery is moving to the west, and that he (the enemy) is felling trees behind him, as elsewhere. The commanding general directs you to push forward your pickets; ascertain if the enemy appears to be retiring, and, if so, to mass your troops in readiness to move in any direction. The corps commanders and General Pleasonton are directed to do the same, and the latter to throw out small cavalry detachments on the various roads leading from our position in the direction of the enemy's retreat, to ascertain the nature and degree of the obstructions therein.

I am, general, very respectfully, your obedient servant,

R. B. MARCY,

Chief of Staff.

HEADQUARTERS ARMY OF THE POTOMAC,
September 19, 1862 - 10.45 p. m.

Major-General PORTER:

GENERAL: General Pleasonton has been directed to have his cavalry and artillery at the river by daylight, and has been informed that you intend to cross at that time, and would co-operate with him.

I am, general, very respectfully, your obedient servant,

R. B. MARCY,

Chief of Staff.

HEADQUARTERS DEFENSES OF WASHINGTON,
September 19, 1862 - 11 p. m.

Major General S. P. HEINTZELMAN, Arlington:

The commanding general, after consulting with the General-in-Chief, directs that you send out a force of cavalry, as suggested by General Birney, to capture the wagons, or, at any rate, to make the attempt. The men (Whitlock and Richmond) who came in with the last party are considered reliable. They will be here at 9 a. m. to-morrow, and will be at once sent over to act as guides. Please give the necessary orders for the movement. It will not be necessary for you to come over in the morning.

By command of Major-General Banks:

RICH'D B. IRWIN,

Captain, Aide-de-Camp, and Actg. Asst. Adjt. General

WASHINGTON, September 19, 1862 - 9.45 a. m.

Major R. H. K. WHITELEY,

U. S. Arsenal, Governor's Island, New York:

Issue at once to Gov. A. G. Curtin, Harrisburg, Pa., two millions of round ball cartridges and one million of .58 caliber cartridges. Request quartermaster to send by quick conveyance and special messenger. Report by telegraph when shipment is made. This dispatch was prepared yesterday, but was mislaid.

JAS. W. RIPLEY,

Brigadier-General, Chief of Ordnance.