Columbia subject headings:
Cities and towns--United States--History--19th century.
Police--United States--History--19th century.
Social classes--United States--History--19th century.
Social conflict--United States--History--19th century.
Harvard subject headings:
Cities and towns--United States--History--19th century.
Police--United States--History--19th century.
Social classes--United States--History--19th century.
Social conflict--United States--History--19th century.
Princeton subject headings:
Cities and towns--United States--History--19th century.
Police--United States--History--19th century.
Social classes--United States--History--19th century.
Social conflict--United States--History--19th century.