Columbia subject headings:
Harvard subject headings:
Prussia (Germany)--Foreign relations--United States.
Prussia (Germany)--History--1815-1870.
Rönne, Friedrich Ludwig v., 1795-1865.
United States--Foreign relations--Germany--Prussia.
United States--History--1849-1877.
Princeton subject headings:
Prussia (Germany)--Relations--United States.
Rönne, Friedrich Ludwig v., 1795-1865.
United States--Relations--Germany--Prussia.