Large scale maps charting the growth of US cities and towns, covering all fifty states.
Includes 8 maps of Northampton (1884-1930), 8 maps of Amherst (1884-1950), 2 maps of Hadley (1929-1943), and other towns in Hampshire, Hamden, and Franklin Counties.
Mass GIS's online mapping tool. "OLIVER can be used to search, display, and share spatial data pertaining to Massachusetts. Users can quickly create and share maps and download data for use in a Geographic Information System (GIS)."
Google Earth
Geographic information (down to the level of street addresses) for sites around the globe combining recent satellite imagery, maps, and other data (demographic, economic, commercial).