Carolyn, As far as I know, their use in -Pudd'nhead Wilson- was the first time fingerprints had been used in fiction to solve a crime and in a trial to prove a point. Certainly, in fictional chronology, because PW is set before the War for Southern Independence, their use in it precedes others. I know of no prior appearance in American literature. Do you know of an earlier use of electrified fences to kill than that in -A Connecticut Yankee in King Arthur's Court-? Or of machine guns to shoot soldiers in trenches in the same novel? While we're at it, aren't the first telephone in fiction, the first long-distance phonecall, the first portable phone, the first courtship by phone, the first overheard phone conversation, the first phone scam, and the first wedding by phone in the short story, "The Loves of Alonzo Fitz Clarence and Rosannah Ethelton"? John H. Davis, Ph.D. Chowan College