Eleven years after beginning to sign himself "Mark Twain," "Saml. L. Clemens" here explains where he originally got his "nom de plume." That is not the same, however, as explaining why he decided to adopt another identity.
"Saml. L. Clemens" (sometimes "Sam.l. L. Clemens," to indicate the abbreviation of "Samuel," is among the signatures he uses most often throughout his career.TRANSCRIPT OF LETTER