Founded in 1867 by D. A. Sanborn, the Sanborn Map Company was the primary American publisher of fire insurance maps for nearly 100 years. Sanborn maps were created to assist fire insurance companies as they assessed the risk associated with insuring a particular property. They include information such as the outline of each building, the size, shape and construction materials, heights, and function of structures, location of windows and doors. The maps also give street names, street and sidewalk widths, property boundaries, building use, and house and block numbers.
How do I read a Sanborn Map? Consult the legend for each map. It can usually be found on the first or second page and varies year to year. Consult Sanborn Map Abbreviations from EDR, Inc. and How to Read Sanborn Fire Insurance Maps from Columbia.
Digital Sanborn Maps - Pennsylvania: Includes Pennsylvania towns outside of Philadelphia. Images downloadable as PDFs.
Sanborn Fire Insurance Maps, Philadelphia: Guide to our microfilm collections.
American Memory Map Collection: The Library of Congress' digitized map collection can be searched by location and images can be downloaded.
CIA Maps: Maps of countries around the world.
David Rumsey Map Collections: Rare 18th and 19th century North American and South American maps and other cartographic materials.
GeoCommunicator: Provides searching, accessing and dynamic mapping of US government data.
NOAA Historical Map and Chart Collection: Search the National Oceanic and Atmospheric Administration's collection.
USGS Historical Topographic Maps: Digital repository of USGS maps printed between 1884 and 2006.