Columbia subject headings:
Canada--Boundaries--United States.
Canada--Foreign relations--Treaties.
Canals--Canada.
Canals--United States.
Saint Lawrence River.
Transportation--Canada.
United States--Boundaries--Canada.
Harvard subject headings:
Canada--Boundaries--United States.
Canada--Foreign relations--Treaties.
Canals--Canada.
Canals--United States
Saint Lawrence River.
Transportation--Canada
United States--Boundaries--Canada.
Princeton subject headings:
Canada--Boundaries--United States.
Canada--Foreign relations--Treaties.
Canals--Canada.
Canals--United States.
Saint Lawrence River.
Transportation--Canada.
Treaties.
United States--Boundaries--Canada.