Columbia subject headings:
United States--Foreign economic relations.
United States--Foreign relations--1865-1921.
United States--Foreign relations--20th century.
Harvard subject headings:
United States--Foreign economic relations.
United States--Foreign relations--1865-1921.
United States--Foreign relations--20th century.
Princeton subject headings:
United States--Foreign economic relations.
United States--Foreign relations--1865-1921.
United States--Foreign relations--20th century.