History 282 American poetry 168 Politics and government 75 Science 60 Social aspects 60 Philosophy 58 Political aspects 51 Rhetoric 50 Poetry 48 History and criticism 40 Women authors 39 English language 31 Social conditions 31 Criticism and interpretation 30 Study and teaching 29 Social life and customs 20 Environmental conditions 18 Government policy 18 Foreign relations 17 City planning 16 Economic conditions 16 Women 16 Environmental aspects 15 Research 15 Environmental policy 14 Intellectual life 14 Social change 14 Democracy 13 American literature 12 Methodology 12