HEADQUARTERS EXPEDITIONARY CORPS,
Port Royal, S. C., December 22, 1861.

General LORENZO THOMAS,

Adjutant-General U. S. Army, Washington, D. C.:

SIR: I have just been informed by Commodore DuPont that a reconnaissance, under Commander Drayton, with the gunboats Pawnee and Seneca, has discovered that the rebel forts at both South and North Edisto are abandoned and guns withdrawn. He also states that a camp of 500 men, in the vicinity of North Edisto, left with their arms on the approach of the gunboats, leaving tents, provision, and camp equipage in his possession.

I think it would be well to occupy Edisto Island, and would de so with part of my own forces were it not necessary to remain here as much concentrated as possible, to be ready for movements already contemplated. Troops pushed up towards Stono Inlet at this time would produce a good effect at Charleston.

From all the information I can gather the South Carolinians are strongly fortifying Charleston Neck and James Island, on the Stono River, and are removing some of the guns from Sumter and the islands for that object, evidently supposing that Charleston is to be attacked by land.

Very respectfully, your obedient servant,

T. W. SHERMAN,

Brigadier-General, Commanding.

PORT ROYAL, S. C., December 23, 1861.

General GEORGE B. McCLELLAN, U. S. A.:

DEAR GENERAL: I have not yet been able to see Commodore DuPont, but have though somewhat of the Charleston problem, which is rather difficult to solve, and will demand much though; but the premises on which much of the data must be based are that the South Carolinians have long come to the conclusion that Charleston in to be attacked by land. Some time ago they removed several of the barbette guns from Sumter and guns from the island batteries to place on the Neck. They have abandoned Edisto Island entirely and removed the guns to some works they have thrown up on the Stono-I believe three in number, including the one at the one at mouth. Several vessels have been sunk in this river. They are making, therefore, a desperate effort to prevent a landing on James Island. What they have done on the north side of Charleston I have not learned. Without looking at the thing satisfactory, yet I am inclined to the opinion that the easiest way to take or destroy the city is by the route of Sullivan's and Morris Island,erecting batteries there, carrying Moutlrie, seizing on Point Pleasant (making a demonstration by Bull's Bay, if necessary), and reducing Sumter, them bringing forward the Navy and shelling the city, assistant by mortar batteries on land, if necessary; but the objection will now arise to this that the channel has been stopped up by a stone fleet. If so stopped, of course this mode would not be so convenient, though it will very possible to shell Charleston from Sumter and Point Pleasant and other points that will readily be seized upon when Sumter has fallen. I have heard it said, however, by officers of the Navy that, if found necessary for the gunboats to enter Charleston Harbor, it can yet be done. As soon as I can get Captain DuPont's views I will write again.