Columbia subject headings:
Historic sites--Conservation and restoration--United States.
Historic sites--Law and legislation--United States.
Historic sites--United States--Conservation and restoration.
Monuments--Conservation and restoration--Law and legislation--United States.
Monuments--Conservation and restoration--United States.
Monuments--United States--Preservation.
Harvard subject headings:
Historic sites--Conservation and restoration--United States
Historic sites--Law and legislation--United States
Monuments--Conservation and restoration--Law and legislation--United States.
Monuments--Conservation and restoration--United States.
Princeton subject headings:
Historic sites--Conservation and restoration--United States.
Historic sites--Law and legislation--United States.
Monuments--Conservation and restoration--Law and legislation--United States.
Monuments--United States--Conservation and restoration.