At the turn of the twentieth century, white, middle-class Americans were in hot pursuit of knowledge about how the other half lived. The impulse to engage a more direct and authentic experience of American life underlies democratic experiments such as the settlement house, and new literary genres such as investigative journalism and undercover literature. In conventional usage, “undercover literature” describes texts written by middle-class and wealthy white Americans who temporarily renounced their worldly comforts to live in disguise among the poor in order to gather raw material for their prose. Scores of undercover narratives were published between the 1880s and 1930s: Progressive-era social investigations, accounts of slumming expeditions, and texts documenting cross-class passages into the world of the waitress, factory laborer, and tramp.Undercover literature is also a particularly female genre. When women gradually outpaced men as undercover authors in the early twentieth century, their dominance within an increasingly recognizable literary tradition registered a gendered pursuit of authority within social scientific, reformist, and literary spheres alike. In this paper, I argue that undercover texts written by American women authors are fundamentally concerned with crossing borders—in spatial, epistemological, and generic terms, and in terms of literary form, movement, and practice. I turn to undercover narratives from Dorothy Richardson's 1905 novel The Long Day: The Story of a New York Working Girl to Cornelia Stratton Parker's 1922 Working With the Working Woman to examine howfemale undercover authors position themselves as mediators and translators uniquely poised to interpret a nation divided. Drawing on their own experience of crossing borders of space, class, and culture, these authors made the traversal of social distance the driving ethos of a new genre of American literature.