Columbia subject headings:
Labor disputes--United States--History--19th century.
Labor unions--United States--History--19th century.
Working class--United States--History--19th century.
Harvard subject headings:
Labor disputes--United States--History--19th century.
Labor movement--United States--History--19th century.
Labor unions--United States--History--19th century.
Working class--United States--History--19th century
Princeton subject headings:
Labor disputes--United States--History--19th century.
Labor movement--United States--History--19th century.
Labor unions--United States--History--19th century.