ProQuest’s Sanborn Maps Geo Edition (1867-1970) is a geo-referenced version of the Sanborn collection for the US, already purchased and available at http://sanborn.umi.com/. The Geo Edition currently contains geo-referenced Sanborn maps from 20 large US cities (none in Iowa, closest is Chicago). Geo-referencing the maps enables layering of the same location from earliest to latestContinue reading “Sanborn Maps GeoEdition — Trial ended August 30, 2010.”