WASHINGTON, September 19, 1862.

Governor PEIRPOINT, Wheeling:

Western Virginia is attached to the Department of the Ohio, headquarters at Cincinnati.* Consult with General Wright about officers and troops to be sent to Colonel Lightburn.

H. W. HALLECK,

General-in-Chief.

HEADQUARTERS CAVALRY DIVISION,
Centreville [Keedysville, Md.], September 20, 1862 - 6.30 a. m.

General MARCY, Chief of Staff:

GENERAL: I have started two brigades of cavalry and a battery of artillery to Jones' Cross-Roads, to proceed in the direction of Williamsport. That force will be amply sufficient for any rebels to be met in that quarter.

The remainder of my command is about getting off for Shepherdstown. The order of Major General Fitz John Porter of yesterday, sending my command to the rear, by the order of General McClellan, and which was transmitted by General Buford, had interfered most materially with a proper pursuit of the enemy. Many of the men of my command have had nothing to eat for two days, and last night, in consequence of the movement to the rear, they missed their trains, and are now starting out without anything. I would also call to the attention of the General commanding the fact that neither provisions nor forage can be obtained in Virginia, that country having been eaten out by the rebels. I have therefore to request that supplies be pushed on to me, if I find it advantageous to proceed on after the enemy, on reaching him. I trust, after the past experience of yesterday, the general commanding will not permit corps commanders to interfere with the cavalry under my command, for it breaks up all my system and plans.

I shall do everything in my power to make up for the time we have lost.

I am, general, very respectfully,

A. PLEASONTON,

Brigadier-General, Commanding Cavalry Division.

HEADQUARTERS ARMY OF THE POTOMAC,
September 20, 1862 - 10.30 a. m.

General FITZ JOHN PORTER:

GENERAL: The commanding general directs that you dispose your guns upon the river bank so as to cover the recrossing of your command, should it become necessary, and send back word to meet the general, who starts for the river soon, provided you want re-enforcements.

Very respectfully,

R. B. MARCY,

Chief of Staff.

HEADQUARTERS SYKES' DIVISION,
September 20, 1862 - 9.15 a. m.

General FITZ JOHN PORTER:

GENERAL: General Lovell's small brigade is three-fourths of a mile from the river. He reports a brigade, at least, of the enemy advancing,

* By Paragraph II, General Orders, Numbers 135, War Department, Adjutant-General's Office, of same date.