This article examines the exclusion of Mexican children from a Louisiana public school in 1915-1916. A school board trustee threw the children out of the school because he saw them as racially mixed and used the socially recognized argument that they had “negro blood.” Although school officials did not see Mexican children as Black or White, their mestizo appearance became a racial marker. Given this time and location—where legal segregation was understood in Black and White terms—Mexicans posed a dilemma because they did not fit into the binary racial system. Although the Mexican consul conducted an investigation and the Mexican Ambassador filed a complaint to the U.S. Department of State, the case was never resolved. We want to broaden the conversation about the racialization of Mexicans in public schools by highlighting the complexities of race and segregation in the deep South.