Timothy J. Gilfoyle is professorof history at Loyola University Chicago where he teaches American urban and social history. His research has focused on the development and evolution of 19th-century urban underworld subcultures and informal economies. He is the author of "A Pickpocket's Tale: The Underworld of Nineteenth-Century New York; City of Eros: New York City, Prostitution, and the Commercialization of Sex, 1790-1920; The Urban Underworld in Late Nineteenth-Century New York: The Autobiography of George Appo;" and co-author of "The Flash Press: Sporting Men's Weeklies in the 1840s". Gilfo...