Columbia subject headings:
Industries--United States.
Labor unions--United States.
United States--Economic conditions--1918-1945.
Working class--United States.
Harvard subject headings:
Industries--United States
Labor unions--United States
Labor--United States
United States--Economic conditions--1918-1945
Working class--United States
Princeton subject headings:
Industries--United States.
Labor unions--United States.
Labor--United States.
United States--Economic conditions--1918-1945.