The Tufts Geospatial Data Repository allows you to search, discover, preview, interact with the map, and retrieve geospatial data from university repositories.
ArcGIS data server, including a number of world, US, and US state data sets that can be brought up directly in ArcGIS (click on a data set and if you have ArcGIS, it will open the program; alternatively, in ArcGIS, click on File – Add Data From ArcGIS Online)
Curated catalog of links to geospatial data sites.
Digital, georeferenced historical maps. Focus on rare 18th and 19th century maps of North and South America, although it also has maps of the World, Asia, Africa, Europe, and Oceania.
Earth Resources Observation and Science Center. Great source for U.S. topographic data and international DEMs.
An open repository of data and maps for the world built by a public community of GeoIQ users.
Spatial Data Infrastructure Links: list of portals by scale.
A guide to Tufts Haiti Geospatial Data Repository and for Online Haiti Geospatial Data repositories.
Free VMAP1 international data.
Great site for state-wide data resources.
GeoData@Tufts allows you to search, discover, preview, interact with the map, and retrieve geospatial data from university repositories.
The Big Ten Academic Alliance Geoportal provides discoverability and facilitates access to geospatial resources, including GIS datasets, web services, and digitized historical maps.