Since Brown’s Wieland in 1798, madness had been prominently featured in the fictional works of many antebellum writers. By the 1830s, insanity became one of main concerns to the American public, as reflected in the extraordinary variety of discussions on mental illness in popular books, newspapers, and periodicals. In contrast to the elitist assumption about the canonical American writers of this period as reclusive figures distant from the popular culture, the major works of Hawthorne, Poe, and Melville indicate that they took a profound interest in emerging medical theories regarding insanity. Relatively few studies, however, have attempted to trace their understandings within the broader context of nineteenth-century theoretical concepts of mental disorder. These three writers wrote much of their fiction during a period that witnessed the rapid development of medical perspectives of the human mind. Drawing upon antebellum psychological discourses, they speculated about the workings of the diseased mind and offered diverse portrayals of mental experience through their fictional characters. In this study, I intend to explore the pervasive presence of monomania in the fiction of Hawthorne, Poe, and Melville. (Konkuk University)