This thesis explores how the characterization of mentally ill characters evolves in literature within the United States in order to understand if and how modern notions of mental illness have impacted American writers’ fictional depictions of insanity. For this reason, this project compares and contrasts American fiction from the 19th century and 21st century. More specifically, the thesis explores the two centuries to trace evolutions in the use of gothic tropes, the progression of the theme of identity, relevant paratexts, and public conversations about fictional mental illness in modern texts—all of which send specific messages about mental health and impact the ways in which the reader understands the characters with mental illness. Ultimately, this thesis argues that the evolved use of tropes, the theme of identity, paratexts, and public conversations suggest there has been a shift from othering characters with mental illness towards accepting these characters and normalizing mental illness as an ordinary and familiar part of the human experience. In short, an increased understanding of mental health accompanies literary choices that create a more sympathetic representation of mental illness overall, even when fiction writers might still rely heavily on 19th-century tropes regarding madness.