HDQRS. DEPT. OF HARPER'S FERRY AND CUMBERLAND,
Camp Keys, Romney, Va., November 6, 1861.

Major General GEORGE B. McCLELLAN,

Commanding the Armies of the United States, Washington, D. C.:

GENERAL: I reported to you by telegram my strength, position, &c. By reference to the map you will see at a glance the importance of holding this place. It is the key to the valley of the upper branches of the Potomac, and commands the counties of Hampshire, Hardy, Pendleton, and Highland, all of which would have been Union counties long since if the Federal troops could have been near them to protect them. The Baltimore and Ohio Railroad forms almost a semicircle around this place, it being from 16 or 28 miles from this place to the two extreme points of the are, comprising a distance of about 60 miles of the line of the road. From here to Winchester it is 40 miles, by the Northwestern turnpike, a very fine road. From here to Monterey, up the valley of South Branch, is about 70 miles, also a good road. Now, in order to afford protection to the Union population in this valley, as well as to protect the Baltimore and Ohio road, a force equal to that which I now have should be wintered here; and should yo desire to strike an offensive blow either on Winchester or Monterey, this is the position to concentrate the force. If I had 8,000 or 10,000 men I could go up this valley and fall on the rear of the rebel forces at Monterey and Greenbrier, and cut off their supplies, and utterly destroy their whole force now in the mountains in front of General Reynolds.

The Baltimore and Ohio Railroad Company are now reconstructing their bridges that the rebels have destroyed over the North Branch and over Patterson's Creek, east of Cumberland, so that in a few days the company will be enabled to run their trains to Green Spring, and distant from here only 16 miles, and to which point I have commenced to-day to construct a telegraph line, which will be done in three or four days. From that point east to a point opposite Hancock, Md., the road can be protected with a small force, if vigilant. So you will see that the Baltimore and Ohio Railroad can be opened for trade, travel, and the use of the Government within a few days if there can be a sufficient force at Harper's Ferry and Martinsburg to force the rebels back from its line.

Respectfully, General, your obedient servant,

B. F. KELLEY,

Brigadier-General, Commanding.

CUMBERLAND, November 7, 1861-10 a.m.

A. V. COLBURN,.

Assistant Adjutant-General:

My force consists of Second Virginia, Sixth Ohio, Third Ohio, and Seventh Indiana, and dismounted battery at Elk Water, under General Dumont; Ninth Indiana, Twenty-fourth Ohio, Twenty-fifth Ohio, Thirty-second Ohio, and dismounted battery on Cheat Mountain, under General Milroy; Howe's battery, Fourth Artillery, one company cavalry, and one company infantry at Beverly, under Colonel Bosley; Thirteenth, Fourteenth, Fifteenth, and Seventeenth Indiana, with Loomis' battery, at Huttonsville, my headquarters; Robinson's Ohio cavalry, distributed; Bracken's Indiana cavalry, resting. Eight regiments, the two dismounted batteries, one company cavalry, and one mounted battery are amply sufficient to hold these post this winter.

J. J. REYNOLDS,

Brigadier-General.