Columbia subject headings:
Boston Harbor (Mass.)--Navigation.
Channels (Hydraulic engineering)--Massachusetts--Boston Harbor.
Federal aid to water resources development--Massachusetts--Boston.
Harbors--Massachusetts--Boston.
Navigation--Massachusetts--Boston Harbor.
Harvard subject headings:
Boston Harbor (Mass.)--Navigation.
Channels (Hydraulic engineering)--Massachusetts--Boston.
Federal aid to water resources development--Massachusetts--Boston.
Harbors--Massachusetts--Boston
Navigation--Massachusetts--Boston.
Princeton subject headings: