Columbia subject headings:
Industries--United States.
Labor laws and legislation--United States.
Working class--United States.
Harvard subject headings:
Industries--United States
Labor laws and legislation--United States
Labor movement--United States.
Labor--United States
Working class--United States
Working class--United States.
Princeton subject headings:
Discrimination in employment--United States.
Industries--United States.
Labor laws and legislation--United States.
Labor unions.
Working class--United States.