Columbia subject headings:
Boycotts--United States--History--19th century.
Hatters--United States--History--19th century.
Trade-unions--Hat trade--United States--History--19th century.
Harvard subject headings:
Boycotts--United States--History--19th century.
Hat trade--Employees--Labor unions--United States--History--19th century.
Hatters--United States--History--19th century.
Working class--United States--History--19th century
Princeton subject headings:
Boycotts--United States--History--19th century.
Hat trade--Employees--Labor unions--United States--History--19th century.
Hatters--United States--History--19th century.