Columbia subject headings:
Social problems.
United States--Economic conditions--1918-1945.
United States--Social conditions.
Working class--United States.
Harvard subject headings:
Labor and laboring classes--United States.
Labor--United States
Social problems
United States--Economic conditions--1918-1945
United States--Social conditions
Working class--United States
Princeton subject headings:
Labor movement--United States.
Social problems.
United States--Economic conditions--1918-1945.
United States--Economic conditions--1945-
United States--Social conditions.
Working class--United States.