The Thirteenth Massachusetts Regiment, on being relieved will be governed by orders from these headquarters.

In view of the recent proclamation of the President, the general directs that, as far as is in your power, you put a stop to all intercourse whatever with the State of Virginia in the vicinity of your posts.

It is not thought probable that any serious attack will for the present be mad upon any of your posts. Should you be forced to call them in and retreat, you will retire upon Frederick. The headquarters will after to-day be fore the present in the vicinity of Hayttstown.

Very respectfully, your obedient servant,

ROBT. WILLIAMS,

Assistant Adjutant-General.

HEADQUARTERS DIVISION OF THE POTOMAC,
Washington, August 20, 1861.

Major General JOHN A. DIX, Commanding, &c., Baltimore, Md.:

GENERAL: Inclosed I send you an order for Captain De Russy's company (K), Fourth Artillery, to proceed without delay to this city to be mounted. The services of that company are indispensable necessary at this place with a light battery. I desire that you replace the company at Fort McHenry by one or more of the best volunteer companies under your command. The First and Fourth Regiments of Pennsylvania Volunteers, now under your command, are required here, to complete General McCall's division. I wish you to forward them to this city as soon as they are relieved by other troops, and in vicinity any three regiments that are there, except Colonel Black's Pennsylvania regiment and the Rhode Island regiment.

This, together with the Sixteenth Massachusetts, will give you two additional regiments. As soon as there are troops enough here to make the capital perfectly secure, I propose to increase your command; but for the present I think the safety of Baltimore can better be scoured by concentrating troops in this vicinity than by leaving them there.

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

GEO. B. MCCLELLAN,

Major-General, Commanding.

HEADQUARTERS DEPARTMENT OF PENNSYLVANIA,
Baltimore, Md., August 20, 1861.

His Excellency THOMAS H. HICKS, Governor of Maryland:

SIR: I should be glad to know your opinion in regard to the measures which should be adopted to break up the active communication manifestly going on between the Eastern Shore of Maryland and the Western Shore of Virginia. there have been rumors for some time that there is a rebel camp in Northampton County, on the Eastern Shore of Virginia. If this be so, it appears to me that it should be broken up. Whatever we do should be well considered, and then carried out with promptness and vigor.

I am, very respectfully, your obedient servant,

JOHN A. DIX,

Major-General, Commanding.