I'm an inland treasure hunter, but i saw this and figured someone on your site may find it useful.
Historical Maps and Charts
Electronic Navigational Charts: NOAA ENCs® ... The Office of Coast Survey's
Historical Map & Chart Collection contains over 20000 maps and charts from the
late 1700s to present day. ... About the Historical Map and Chart Collection ...
www.nauticalcharts.noaa.gov/csdl/ctp/abstract.htm
Historical Maps and Charts
Electronic Navigational Charts: NOAA ENCs® ... The Office of Coast Survey's
Historical Map & Chart Collection contains over 20000 maps and charts from the
late 1700s to present day. ... About the Historical Map and Chart Collection ...
www.nauticalcharts.noaa.gov/csdl/ctp/abstract.htm