["Social Science Quarterly, EarlyView. ", "\nAbstract\n\nObjective\nThis study examines the improvement of U.S. natives’ social distance attitudes toward Southern, Central, and Eastern (SCE) European ancestry groups in the post‐World‐War II United States, applying the idea that prejudice against these groups was due to racial/ethnic prejudice and social class prejudice.\n\n\nMethods\nAnalyzing data from the Bogardus surveys and other published sources, the study tests the proposition that U.S. natives’ social distance attitudes toward SCE European ancestry groups improved because social class prejudice against these groups diminished as the groups’ educational attainment levels increased from the second‐ to third‐generations.\n\n\nResults\nContrary to modernization and classical assimilation theories, the favorable trend in U.S. natives’ social distance attitudes toward SCE European ancestry groups was unaffected by the groups’ intergenerational educational mobility.\n\n\nConclusion\nThe decline in prejudice against SCE European ancestry groups in the postwar United States resulted from a decrease in racial/ethnic prejudice against these groups, independently of social class prejudice.\n\n"]