OSM US is incredibly excited to announce the latest Charter Project: OldInsuranceMaps.net (OIM)!
If you’re a map nerd you’ll remember ever seeing a Sanborn Insurance Map in person. They often come in absolutely massive tomes that were once perhaps the closest you could get to OpenStreetMap before the digital age; over the years, each page becomes a collage of small cutouts of paper pasted over streets since renamed, or buildings since demolished. They are both beautiful pieces of artwork and one of the most accurate references for geographic data in the United States from 1867 into the 1960s. Sanborn Maps are a valuable resource for historical mappers and researchers (as briefly mentioned in our OpenHistoricalMap Mapper Highlight post), and thanks to OIM their georeferenced information is much more accessible.
A Sanborn map of Richmond, Virginia at the Library of Congress. Notice where paper cutouts have been layered over the original map.
Adam Cox began OIM while at Louisiana State University back in 2022 and today the platform hosts over 1200 Sanborn maps primarily sourced from the Library of Congress. These maps have such broad appeal that a wide range of people have been drawn to the project, from hobbyists exploring the history of their hometown to scholars undertaking large research studies and professionals working on redevelopment. It is very likely that a place that you care about can be explored via OIM, and there is a strong community of volunteer georeferencers to connect with (in case you need another mapping rabbit hole to fall down).
Anyone can request that their city or town’s Sanborn map(s) be added to the website. Scanned maps can then be georeferenced by placing ground control points and digitally stitching each page together. Thanks to Adam’s work, the interface is intuitive to learn and accessible no matter your existing knowledge of geography and GIS. It’s an innovative combination of historical archivism, open-sourced technology, and crowdsourced knowledge.
Sanborn maps at the New Orleans Public Library, CIty Archives and Special Collections
Our project exists to facilitate the creation of open historical map materials, and to do so in a way that is accessible, engaging, and robust. Becoming part of the Charter Project program is the perfect way to bring this work to the next level, because the ethos of the OSM US organization (and all the great people within it!) resonates so strongly with what our platform is all about.
OIM joins YouthMappers, Yesterdays, and OpenHistoricalMap as an OSM US Charter Project. In particular, the OSM US team is excited to see increased collaboration and synergies between OHM, Yesterdays, and OIM. Each tool is individually excellent at collecting and portraying historic geographic data, and many contributors to one platform naturally include another in their workflows. For example, mappers contributing to OHM already create georeferenced mosaics on OldInsuranceMaps.net and use them directly while editing OHM as historical reference layers to trace from, and Yesterdays includes Sanborn maps from OIM as a base layer to help users place historical images accurately.
University of Richmond student with a digital display built with the help of OldInsuranceMaps.net
Get Involved with OIM
Any project in the OpenStreetMap ecosystem is invited to apply to become a Charter Project; applications are always open and reviewed on a rolling basis. Visit the Community & Charter Projects page to learn more.