In 1849--months before the term "confidence man" was coined to identify a New York crook--Thomas Powell (1809-1887), a spherical, monocled, English poetaster, dramatist, journalist, embezzler, and forger, landed in Manhattan. Powell in London had capped a career of grand theft and literary peccadilloes by feigning a suicide attempt and having himself committed to a madhouse, after which he fled England. He had been an intimate of William Wordsworth,...