Columbia subject headings:
Harvard subject headings:
United States--Economic conditions--20th century.
United States--Foreign relations--20th century.
United States--History--20th century.
Princeton subject headings:
Globalization--History--20th century.
Imperialism--History--20th century.
United States--Economic conditions--20th century.
United States--Foreign relations--20th century.
United States--Politics and government--20th century.