1 Although the order of the initials in this monogram has not been established beyond all doubt, it is likely that Clemens used stationery he had borrowed in Hartford from Susan Lee Warner, wife of Charles Dudley Warner. Clemens may have intended this document as a draft for a form letter. On 9 June 1877, the San Francisco Alta California printed in its front page “Brevities” column a virtually identical letter, to John A. McPherson, dated 29 May, presumably 1877. In these letters Clemens gave essentially the same explanation of his pen name that he had been publicly committed to since at least late January 1873, when he included it in the autobiographical sketch he provided as “data” to Charles Dudley Warner (L5, 283). For a discussion of the discrepancies between Clemens’s account and documented fact, including Clemens’s incorrect death date for Isaiah Sellers (actually 6 March 1864), whose supposed prior use of “Mark Twain” remains unconfirmed, see Kruse, 2–25.