Columbia subject headings:
Communication and traffic--United States.
Railroads and state--United States.
Railroads--United States--History.
Railroads--United States.
Transportation--United States--History.
Transportation--United States.
Harvard subject headings:
Communication and traffic--United States
Railroads and state--United States.
Railroads--United States
Railroads--United States--History
Transportation--United States
Transportation--United States--History
Princeton subject headings: