Labor unions History 288 Labor movement 110 Political activity 81 Industrial relations 65 Working class 54 Politics and government 48 Employees 37 Organizing 37 Social conditions 34 Strikes and lockouts 32 Labor 29 Officials and employees 29 Economic conditions 25 Labor policy 23 Collective bargaining 21 Labor laws and legislation 18 Coal miners 17 International labor activities 17 Agricultural laborers 16 Employment 16 Labor leaders 16 African Americans 13 Automobile industry and trade 13 Automobile industry workers 13 Economic aspects 13 Management 13 Migrant agricultural laborers 13 Social aspects 13 Law and legislation 12