Other
Socialism
4
Wages
3
Economic conditions
2
Anthracite coal
1
Capitalism
1
Coal trade
1
Cost and standard of living
1
Democracy
1
Economic history
1
Economics
1
History
1
Income
1
Labor and laboring class
1
Labor and laboring classes
1
Monopolies
1
Peace
1
Poetry
1
Politics and government
1
Revolutions
1
Social history
1
Social problems
1
Social structure
1
Trusts, Industrial
1
World War, 1914-1918
1