Economic aspects History 673 Economic conditions 305 Social aspects 268 Agriculture 192 Government policy 152 Finance 139 more ... Political aspects 135 Technological innovations 125 Emigration and immigration 109 Education, Higher 106 Education 104 Law and legislation 103 Social conditions 93 Economic policy 90 Slavery 83 Globalization 81 Politics and government 78 Environmental aspects 57 Environmental policy 57 Race relations 57 Universities and colleges 56 World War, 1939-1945 55 Taxation 52 Agriculture and state 51 Commerce 51 Foreign relations 48 African Americans 47 Income distribution 47 Management 46 less ...