Labor unions 45 Labor 32 History 31 Labor movement 29 Working class 25 Employment 16 Coal miners 11 more ... Labor and laboring classes 11 Women 9 Child labor 8 Labor laws and legislation 8 African Americans 7 Labor supply 7 Social conditions 7 Coal mines and mining 6 Convict labor 5 Dwellings 5 Economic conditions 5 Hours of labor 5 Housing 4 Musicians 4 Anthracite coal industry 3 Coal trade 3 Defense industry 3 Emigration and immigration 3 Labor disputes 3 Labor market 3 Law and legislation 3 Periodicals 3 Pickets 3 Prisons 3 Railroads 3 Religious aspects 3 Social aspects 3 Societies, etc 3 Wages 3 African American children 2 African American musicians 2 Agriculture 2 Aircraft industry 2 less ...