The Burdens of Responsibility traces the emergence of moral responsibility as both a concept and problem in the nineteenth-century United States. Drawing on a range of sources –works of literature, philosophy, domestic manuals, newspaper archives – I show how many Americans began to conceive of moral responsibility as distinct from both duty and rules of behavior prescribed by traditional social roles. Although ethicists today take this distinction for granted, it was an emergent and problematic space in the nineteenth-century United States, brought into being by historical forces, including the rise of market capitalism, abolition, changing women’s roles, and increasing concern with the responsibilities (not merely the rights) of democratic citizenship. I argue that American authors, thinkers, and citizens were compelled to negotiate the tension between familiar notions of duty (fixed, prescribed, automatic) and new calls for responsibility (improvised, self-authored, contextual).