Columbia subject headings:
Radicalism--United States--History.
Right and left (Political science)
Socialism--United States--History.
Working class--United States--History.
Harvard subject headings:
Labor movement--United States--History
Radicalism--United States--History.
Right and left (Political science)
Socialism--United States
Socialism--United States--History
Working class--United States--History
Princeton subject headings:
Labor movement--United States--History.
Radicalism--United States--History.
Right and left (Political science)
Socialism--United States--History.