Although the illness narrative genre became more popular in the mid-20th century, Americans have been writing illness narratives throughout American history. Writing Contagion focuses on American epidemics to see how these outbreaks spurred Americans into telling their stories. Looking at book-length narratives of illness and disability, the author traces the development and lineage of illness narratives from early American nonfiction writing, to literary modernism and to contemporary memoir. Viewing illness narratives as intensely interdisciplinary, the author argues that to understand both the importance and influence of this genre within American literature, illness narratives need to be read through literary, disability studies, and medical humanities frameworks to challenge ableist assumptions and demonstrate how illness narratives are of both historical and literary importance in America.