This article focuses on how public schools have functioned in the ideological production of race in America and their critical role in shaping the way Americans understand specific definitions of race as well as the muted rules of racial etiquette. The author analyzes American schools as racializing institutions, that is institutions with the power to inscribe particular notions about race as part of the knowledge set of the educated citizen. The author contends that both spoken and unspoken lessons on human diversity shaped the way Americans understood the ambiguous concept of "race." Based on a detailed analysis of teachers' firsthand accounts of classroom practice, the author argues that educational discourse on race underwent a paradigmatic shift during the brief time span of World War II.(Contains 93 footnotes and 4 figures.)