1 Fuller had written twice—on 21 August and on 3 September—since receiving Clemens’s letter of 8–10 July. In the first letter, he offered an investment opportunity (CU-MARK):

Clemens was “a member of the Govment” briefly in late 1867, when he acted as secretary for Senator Stewart of Nevada. In “The Facts Concerning the Recent Resignation,” published in the New York Tribune on 27 December 1867, he claimed that the secretary of the treasury had called him an ass for suggesting that “a few conundrums distributed around through his Treasury report would help the sale of it” (SLC 1867; L2, 109–10 n. 2, 112, 139 n. 4). The creator of Fuller’s “letter envelope,” Addison C. Fletcher of New York City, had received United States patent number 127,330 on 28 May 1872 for his invention, a “letter-sheet blank, having its inner fold cut away or punctured at its end so that mucilage or other adhesive material applied to the corners of the outer fold or flap will seal both folds and the back together at one operation” (Official Gazette, 1:539). Fuller wanted Clemens to persuade his Hartford friend Marshall Jewell, former three-term governor of Connecticut, minister to Russia, and since 3 July the United States postmaster general appointee, to officially adopt it (L4, 396 n. 1; “The Postmaster Generalship,” New York Times, 4 July 74, 4). Clemens declined the offer, in a letter not known to survive, before 3 September, when Fuller wrote again. This time Fuller used one of Fletcher’s blanks and enclosed a letter, now lost, in which Fletcher, who was not coming easily to terms, apparently claimed his invention’s distinction from its English counterpart (CU-MARK):

The “certain Brooklyn party” has not been identified.