How to Sanborn*:A quick how-to guide to get you started with the Sanborn Map Collection at the University of Illinois at Chicago. *Yes, we're using Sanborn as a verb.
Finding the Sanborn fire insurance map you’re looking for is not always as simple as it sounds. You will need two things to find the map you are looking for: the Chicago Volume Key and the Sanborn Key Map. The Chicago Volume Key is a map of the Chicago Area showing volume numbers and locations. The Sanborn Key Maps are the maps at the beginning of each volume showing sheet numbers and locations.
This guide will take you step by step through finding the map for you:
Produced for over a century, more than 660,000 Sanborn maps chart the growth and development of more than 12,000 American towns and cities. Sanborn maps are large-scale plans of a city or town, drawn at a scale of 50 feet to an inch.
The Sanborn maps were created in real time as the Chicago area was growing very quickly and it was not a mapping project that was planned or organized. Instead it was done on an “as needed” basis for the benefit of the clients of the Sanborn Map Company. As a result, there can be a lack of logical organization. But generally we can find the areas that you are interested in seeing.
The area in Cook County is more complicated because in part the City of Chicago has annexed areas that were previously outside the city limits and when that annexation occurred has some effect on the volume numbers and/or letters. Sanborn maps for the Cook County area have numbered volumes starting with 1 in the beginning until the present with volume 49. The maps were originally just in the central part of Chicago, but as the city grew, the number of volumes increased. Also, areas outside the city were in lettered volumes and with the passage of time and growth of the county the lettered volumes increase as well from A through C, and, eventually, A through K.