HDQRS. DEPT. OF WASHINGTON, 22nd ARMY CORPS, July 9, 1864.

Major D. W. C. THOMPSON,
Commanding at Muddy Branch:

MAJOR: The major-general commanding directs that you watch closely the movements of the rebel force reported to have crossed the Monocacy. In the event of the force moving in the direction of Washington, or the Baltimore and Washington Railroad, you will draw in gradually your pickets and keep your command on the flank of the column, moving parallel with it and keeping your advance ahead of it, that information from time to time, as you may see fit, may be furnished these headquarters. The object of this, you will understand, is that the department may be duly apprised of the movement of the enemy, that none of your pickets may be cut off, and that you may be constantly in position to render such service as may be required from your command.

I am, major, very respectfully, your most obedient servant,

J. H. TAYLOR,

Chief of Staff and Assistant Adjutant-General.

HEADQUARTERS CAVALRY CAMP, Muddy Branch, July 9, 1864.

Colonel J. H. TAYLOR,

Chief of Staff:

COLONEL: I have the honor to acknowledge the receipt of your letter of this date with directions for the disposition of my command. I have ordered my pickets withdrawn above Edwards Ferry, and have swung them round to the right at Poolesville, Dawsonville, Germantown, and Gailthersburg, with patrols for mouth of the Monocacy to Barnesville, Clarksburg, and toward Brookeville, so as to cover my camp and the roads to Washington from Frederick, as well as my force will permit. I have placed all my surplus property on a canal-boat ready to send down, and have everything ready to break in light marching order as soon as it may be necessary. I have organized a fatigue party to fell trees and obstruct the roads if the enemy should move toward Washington. Captain Eighbrodt, Company E, Second Massachusetts Cavalry, has just come in form the mouth of the Monocacy, where he has been picketing, with the information that our troops and the rebels have been fighting for several hours at Burkittstown [Buckeystown], on the Monocacy. The cannonading commenced about 11 a. m., and was plainly heard in my camp. Also, that about 7,000 rebel cavalry and artillery passed through Adamstown, toward the Monocacy, this morning. Some of Captain Eigenbrodt's men went within one that General Ricketts had arrived with some 6,000 men, near Frederick, from the Army of the Potomac, and that his forces were engaged to-day; also that the rebels who went through Adamstown this morning were commanded by General Lewis. A large smoke was seen later this afternoon near and to the left of Sugar Loaf Mountain from the Potomac, which might have been the bridge over the Monocacy at the Junction. I will do all I can to hinder