This article discusses the contributions of five pioneers to shaping antebellum literary journalism: Lydia Maria Child (1802–80), Walt Whitman (1819–92), Margaret Fuller (1810–50), Frederick Douglass (1818–95), and Fanny Fern (1811–72). Noting the five writers’ affiliations with such movements as abolitionism, Transcendentalism, women’s rights, and prison reform, the article suggests that their conceptions of American literary journalism connect the genre with social reform. It proceeds to situate them politically with respect to each other and to identify the innovations each introduced into literary journalism, illustrating them with examples from their texts. These innovations include Child’s use of free association; Whitman’s of imaginary dialogues between speakers articulating opposing views; Fern’s of a slangy, conversational style; Fuller’s of novelistic and theatrical techniques of representing events; and Douglass’s rhetoric of persuasion embellished by parataxis and antithesis. The article concludes by tracing continuities between the five antebellum pioneers and three twentieth-century literary journalists who likewise championed progressive causes: Langston Hughes, Agnes Smedley, and Meridel Le Sueur.