History Politics and government 50 Social conditions 30 Economic conditions 25 Indians of South America 19 Political violence 16 Social aspects 15 more ... Social life and customs 15 Insurgency 13 Guerrillas 11 Intellectual life 11 History and criticism 10 Civilization 9 Political aspects 9 Violence 9 Economic aspects 8 Railroads 8 Study and teaching 8 Education 7 Foreign relations 7 Land tenure 7 City planning 6 Colonies 6 Commerce 6 Economic policy 6 Education, Higher 6 Historiography 6 Nationalism 6 Peasants 6 Political activity 6 less ...