Reports of the enemy having returned to Harper's Ferry and had driven the occupants to this shore reached me yesterday. I immediately dispatched a strong force to take position in the vicinity of Sharpsburg and protect all parties on this side of the river, and drive back any force which may attempt to cross.

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

R. PATTERSON,

Major-General, Commanding.

[Inclosure.]

HAGERSTOWN, MD., June 21, 1861.

Colonel E. D. TOWNSEND,

Washington City:

The telegram of the General-in-Chief of yesterday was received at midnight. To carry out proposed plan I think involves a change of depot to Frederick and evacuation of Williamsport and Hagerstown. With an enemy close at had, a move suddenly, with present amount of transportation, necessitates sending a large mass of stores back to Harrisburg or their abandonment.

Maryland Heights can be secured, and Frederick also, and a strong force of infantry, some cavalry, and artillery sent via Frederick to Leesburg to sweep the enemy from that point to Alexandria. If no blow is to be struck here, and this meets the views of the General-in-Chief, I will at once commence moving, and be in position to act at the earliest practicable moment. I send a regiment to-day to Frederick at the urgent solicitation of the governor. I shall write in full by mail. Reconnaissance of heights being made. Send your telegrams via Harrisburg, Chambersburg, &c. Frederick line cannot be relied upon.

R. PATTERSON,

Major-General, Commanding.

HEADQUARTERS DEPARTMENT OF PENNSYLVANIA, Hagerstown, Md., June 21, 1861.

General McCall,
Harrisburg, Pa.:

Place send the following to Colonel Wallace:

Five thousand cartridges and six thousand caps for rifle (caliber .54 inch) and eight thousand extra carps were dispatched to you on Tuesday at noon. Yesterday Jerome Closson was sent to report the condition of the country east of Cumberland. The force you specially wish is not here. The commanding general now wishers you to join this force, partly in anticipation of immediate active operations, and in part to be relieved of constant anxiety for you when it is impossible to render you relief, and leaves the route to your judgment.

F. J. PORTER,

Assistant Adjutant-General.

HAGERSTOWN, MD., June 21, 1861.

Colonel SAMUEL YOHE,

First Regiment Pennsylvania Vols., near Funkstown, Md.:

COLONEL: The commanding general directs you, on arrival at Frederick, to notify Governor Hicks of the presence of yourself and regiment, prepared to aid in the execution of the laws and to maintain order. You will carefully guard against your men being induced to commit acts of violence, or in any manner taking part in redesign private wrongs,