Columbia subject headings:
Economics--United States--History.
Protectionism--United States--History.
United States--Economic conditions--1865-1918.
United States--Economic policy--To 1933.
Harvard subject headings:
Economics--United States--History
Protectionism--United States--History.
United States--Economic conditions--1865-1918.
United States--Economic policy--To 1933.
Princeton subject headings: