Looking at Stephen Crane’s Maggie and William Faulkner’s Light in August, this chapter suggests that racial in-betweenness may be one of the driving forces of American literature. At the turn of the twentieth century, the distinction between whiteness and blackness plagued not only literary authors, but also legal institutions. In a series of court cases, judges had to decide which immigrant groups counted as white and could hence be naturalized. This chapter proposes that at this juncture, law and literature are closely interconnected. At a time when the judiciary struggled to make sense of petitioners who were racially in-between, literary texts zoom in on figures who are either mixed race or racially indeterminate. Crane’s novella presents the idea that in the late nineteenth century, the Irish were seen as “whites on probation.” Faulkner’s novel focuses on a protagonist who is rumored to be a “mulatto”, but turns out to be half Mexican. Focusing on the “off-whiteness” of Irish and Mexican characters in American literature, this chapter argues that whiteness is ultimately a fiction, and that it is in the pages of literature that the construction of whiteness can best be observed.