History 1,079 Politics and government 193 Social life and customs 176 History and criticism 163 Social conditions 113 Frontier and pioneer life 99 Mexican Americans 81 World War, 1939-1945 80 Social aspects 74 Description and travel 72 Antiquities 69 Race relations 68 Indians of North America 67 Presidents 67 African Americans 61 Political aspects 59 Anesthesia 58 Natural history 56 Campaigns 54 Criticism and interpretation 52 Folklore 49 American literature 44 Women 44 In literature 43 Study and teaching 43 Economic conditions 42 Ranch life 41 Vietnam War, 1961-1975 41 Ethnic relations 39 Education 38