MapScholar is an interactive visualization tool for historic map collections.  It gives any scholar the independent means of gathering high-resolution images, analyzing them in rich geospatial contexts, and using them to illustrate new interpretations.  MapScholar enhances history of cartography scholarship by making it possible to mount stunning web displays of map collections assembled from libraries around the world–for free. MapScholar’s key innovation is how it brings maps together–regardless of the archive in which they sit–for the purpose of generating new knowledge about human perceptions of geographic space.