Columbia subject headings:
Harvard subject headings:
Labor movement--United States--History--19th century.
Labor movement--United States--History--20th century
Racism--United States--History--19th century
Racism--United States--History--20th century
United States--Race relations
Princeton subject headings:
Labor movement--United States--History--19th century.
Labor movement--United States--History--20th century.
Racism--United States--History--19th century.
Racism--United States--History--20th century.
United States--Race relations.