TLS, one page, 8 x 11, personal letterhead, August 21, 1940. In part: “Enclosed is the manuscript you so kindly sent me which I have read with interest. My immediate commitments are such that I could not undertake a biographical study of Gen. Porter…only one who has through years of toil sifting this evidence to its essential points, can render an adequate or fair judgement of Gen. Porter.”; and a bold ink signature, “Carl Sandburg,” on an off-white 4 x 2.5 slip. In fine condition, with intersecting folds to letter, one through a single letter of signature, as well as some mild toning. RRAuction COA.