Author of such classics as The Adventures of Tom Sawyer, Huckleberry Finn and A Connecticut Yankee in King Arthur's Court. Fountain pen signature, 'Truly Yours, Mark Twain, May 1880,' on a white 4.5 x 3 sheet cut from a longer letter. Large, bold signature. In fine condition, with a vertical fold through one letter of the signature and the paraph, a horizontal fold touching a couple of letters of the signature, a bit of adhesive residue on the reverse from a previous mounting. COA John Reznikoff/PSA/DNA and RRAuction COA.