This dissertation confronts the absence of biological sisterhood in modern critical examinations of nineteenth-century literature. Seizing upon the popular pattern of using familial rhetoric to frame political and social debates in early U.S. history, this project explores women writers who entered those debates via their fictional biological sisters. The biological tie equalizes the sisters' social standing and allows them to function as citizen models within the family - symbolic of the nation. Using popular nineteenth-century serial fiction and collected letters among actual sisters of the same period, chapter one identifies three traits of sisterhood that dominate the fiction and the letters: the importance of the elder sister as a behavioral model, a deep commitment to the long-term well-being of a sister, and the authorial trend of comparing and contrasting sisters. Taken together, these traits allow authors to wield their sisters as models who offer behavioral cues for citizen readers while insisting upon the dedication of one sister-citizen to the well-being of her national sister-citizens. Chapter two addresses Rebecca Rush's Kelroy, a novel that follows the Hammond sisters as they react to the machinations of their mother, Mrs. Hammond, a metaphorical stand-in for Britain. The text is Rush's warning to citizens who do not adequately resist "Mother Britain's" interference. Chapter three examines Ann S. Stephens' Mary Derwent, a text that follows the Derwent Sisters and casts younger sister Mary as the Indian-equivalent "Other" through her physical deformity, a hunchback. Rush disparages those who support Indian Removal policies and advocates for Indian inclusion into the American family. Finally, chapter four examines Elizabeth Stoddard's The Morgesons, a novel published during the Civil War. Despite no overt war references, Stoddard's setting keenly reflects the national landscape, as sisters Veronica and Cassandra exist within a house divided. Following the death of Mrs. Morgeson, Stoddard ponders the post-war future of the United States as the sisters rebuild their lives in a newly reconfigured house under new leadership. Each novel in this project begs for reconsideration as a text that is actively engaged with contemporary national concerns, an engagement that is voiced through the authors' sororal creations.