A decade-long project on the migration of Italian laborers around the world during the nineteenth and twentieth centuries points to the methodological challenges, theoretical debates, and some of the rewards of transnational analysis of class, ethnicity, and gender in the making of modern national states. Analyses of internationally mobile laborers historicize current transnational studies, problematize the historiography of national groups, and reveal how profoundly—and usually also how “nationally”—every multiethnic nation-state understood relations among ethnicity, race or color, class, and gender.