Three resources that may be helpful are:
NOAA:
http://www.charts.noaa.gov/OnLineViewer/AtlanticCoastViewerTable.shtml
http://www.nauticalcharts.noaa.gov/csdl/ctp/abstract.htm
http://www.nauticalcharts.noaa.gov/
Rhode Island Maritime Archaeology Project. Their main page is http://www.rimap.org/. They have a historical map collection that is not yet up online: http://www.rimap.org/index.php?option=com_content&view=article&id=114:rimap-revolutionary-war-heritage-trails&catid=38:rokstories-frontpage.
URI Pell Marine Science Library may also be helpful: http://www.gso.uri.edu/facilities/pell-marine-science-library.
