Columbia subject headings:
Harvard subject headings:
Middle class--United States--Economic conditions--20th century.
United States--Economic conditions--20th century.
United States--Economic policy--20th century.
Welfare state--United States--History--20th century.
Princeton subject headings:
Middle class--United States--Economic conditions--20th century.
United States--Economic conditions--20th century.
United States--Economic policy--20th century.
Welfare state--United States--History--20th century.