History 45 Social conditions 14 Periodicals 13 Slavery 12 Economic conditions 10 Histoire 9 Societies, etc 8 more ... Politics and government 7 Economic aspects 6 Emancipation 6 Enslaved persons 6 Wages 6 African Americans 5 Political aspects 5 Social aspects 5 AIDS (Disease) 4 Chinese Americans 4 Emigration and immigration 4 French 4 HIV-positive persons 4 Patients 4 Railroads 4 Study and teaching 4 Aspect social 3 Economics 3 Ethnic relations 3 Indians of North America 3 Irish Americans 3 Philadelphia (Pa.)--Politics and government--20th century 3 Slave trade 3 Socialism 3 Urban renewal--Pennsylvania--Philadelphia 3 World War, 1939-1945 3 Accounts--19th century 2 Agriculture 2 Anthracite coal 2 Artists--Pennsylvania--Philadelphia--20th century 2 Asian Americans 2 Avenue of the Arts (Philadelphia, Pa.) 2 Banks and banking 2 less ...