“Locating the Modern Mexican in Josephina Niggli’s Step Down, Elder Brother” turns away from Niggli’s more popularly studied Mexican Village to her second novel, published in 1947. The shift to Step Down, Elder Brother, which focuses on the industrial city of Monterrey instead of the Mexican village, opens up a set of questions about what it means to be Mexican in the modern, post-Revolutionary moment. Niggli’s interest in the Mexican frontier’s major city provides a surprising definition that runs counter to the one provided by her first novel. Instead of focusing on discourses of mestizaje and indigenismo as the defining qualities of Mexican identity, she suggests “Mexican” is a spatial category instead of a racial one. Further, this essay contends that this definition reconfigures Niggli’s relationship to a Chicana literary tradition, where she has been positioned as a precursor to “the new mestiza,” thus interrogating the use of the autobiographical in literature and intersecting issues of racial and gendered authenticity.