February 28th, 1861.
1st. It is not more than possible to supply this Fort, by ruse, with a few men or a small amount of provisions- Such is the unceasing vigilance employed to prevent it.
2d. To do so, openly, by vessels alone, unless they are shot-proof, is virtually impossible – so numerous and powerful are the opposing Batteries: and no vessel can lay near the Fort without being exposed to continual fire. And the Harbor could, and probably would, whenever necessary, be effectually closed – as one channel has already been.
3d. A projected attack, in large force, would draw to this Harbor all the available resources, in men and materiel, of the contiguous States. Batteries, of guns of heavy calibre, would be mulitplied rapidly and indefinitely: at least 20.000 men, good marksmen and trained for months past with a view to this very contingency, would be concentrated here before the attacking force could leave Northern ports. The Harbor would be closed: a landing must be effected at some distance from our guns, which could give no aid. Charleston Harbor would be a Sebastopol in such a conflict, and unlimited means would probably be required to ensure success: before which time the garrison of Fort Sumter would be starved out.
Bvt Capt & 1st Lieut.
SOURCE: Abraham Lincoln Papers at the Library of Congress, Washington, D.C.