Columbia subject headings:
China--Commerce--United States--History--18th century.
Empress of China (Ship)
United States--Commerce--China--History--18th century.
Harvard subject headings:
China--Commerce--United States--History--18th century.
Empress of China (Ship)
United States--Commerce--China--History--18th century.
Princeton subject headings:
China--Commerce--United States--History--18th century.
Empress of China (Ship)
United States--Commerce--China--History--18th century.