Columbia subject headings:
Capitalists and financiers--Kentucky--History.
Coal mines and mining--Kentucky--History.
Energy industries--Kentucky--History.
Kentucky--Economic conditions.
Kentucky--History.
Kentucky--Politics and government.
Kentucky--Social conditions.
Wealth--Kentucky--History.
Harvard subject headings:
Capitalists and financiers--Kentucky--History.
Coal mines and mining--Kentucky--History.
Energy industries--Kentucky--History.
Kentucky--Economic conditions.
Kentucky--History.
Kentucky--Politics and government
Kentucky--Social conditions.
Wealth--Kentucky--History.
Princeton subject headings:
Capitalists and financiers--Kentucky--History.
Coal mines and mining--Kentucky--History.
Energy industries--Kentucky--History.
Kentucky--Economic conditions.
Kentucky--History.
Kentucky--Politics and government.
Kentucky--Social conditions.
Wealth--Kentucky--History.