Columbia subject headings:
Folk music--United States--History and criticism.
Folk songs, English--United States--History and criticism.
Railroads--Songs and music--History and criticism.
Railroads--Songs and music.
Harvard subject headings:
Folk music--United States--History and criticism
Folk songs, English--United States--History and criticism
Railroads--United States--Songs and music--History and criticism.
Princeton subject headings:
Folk music--United States--History and criticism.
Folk songs, English--United States--History and criticism.
Railroads--United States--Songs and music--History and criticism.