Oldinsurancemaps.net is now a Charter Project
OldInsuranceMaps.net Joins the OSM US Charter Project
August 25, 2026 | Published by OpenStreetMap US Staff
The OpenStreetMap US (OSM US) team is thrilled to announce that OldInsuranceMaps.net (OIM) has officially become a Charter Project!
The Magic of Sanborn Maps
For those with a passion for cartography, the name Sanborn Insurance Map likely evokes a specific image. These maps were traditionally housed in enormous volumes—essentially the analog precursor to OpenStreetMap. Over decades, these books became living documents, with obsolete outdated sections replaced by small paper cutouts pasted over streets that were renamed or buildings that were torn down.
These volumes are more than just data; they are stunning works of art and serve as some of the most precise geographic records for the United States, spanning the era from .
Example: A Richmond, Virginia map from the Library of Congress, showing the layered paper cutouts used for updates.
What is OldInsuranceMaps.net?
Founded in 2022 by Adam Cox during his time at Louisiana State University, OIM has grown into a powerhouse of historical data. The site currently hosts over 1,200 Sanborn maps, the majority of which are sourced from the Library of Congress.
The platform attracts a diverse user base, including:
- Hobbyists tracing the evolution of their own neighborhoods.
- Academics conducting extensive historical research.
- Professionals specializing in urban redevelopment.
How the Process Works
The project relies on a blend of open-source tech and community effort. The workflow for adding a map looks like this:
Thanks to Adam's design, the interface is intuitive, meaning you don't need a degree in GIS (Geographic Information Systems) to navigate it. It represents a unique intersection of crowdsourced knowledge, open-source technology, and historical archivism.
Sanborn maps preserved at the New Orleans Public Library's Special Collections.
A New Chapter as a Charter Project
The mission of OIM—to create open, robust, and engaging historical map materials—aligns perfectly with the core values of OSM US. By joining the Charter Project program, OIM can scale its impact.
OIM now stands alongside other prestigious Charter Projects:
- YouthMappers
- Yesterdays
- OpenHistoricalMap (OHM)
Ecosystem Synergies
The OSM US team is particularly excited about the "cross-pollination" between OIM, OHM, and Yesterdays. While each tool is powerful on its own, they are even better when used together.
| Tool | Primary Function | Synergy with OIM |
|---|---|---|
| OHM | Historical Mapping | Mappers use OIM mosaics as reference layers to trace data into OHM. |
| Yesterdays | Historical Imagery | Uses OIM maps as base layers to help users precisely place old photos. |
| OIM | Georeferenced Sanborns | Provides the foundational spatial data for the other two. |
A University of Richmond student utilizing a digital display powered by OIM data.
How to Get Involved
Whether you want to dive into a "mapping rabbit hole" or support the infrastructure, there are many ways to help:
- Explore the archives at
oldinsurancemaps.net - Help georeference maps to expand the library
- Provide financial support via OSM US donations
- Join the conversation in the
#oldinsurancemapsSlack channel - Contribute code or report issues on GitHub
For those interested in the technical side, contributions often happen via Git:
git clone https://github.com/oldinsurancemaps/project.git
cd project
npm install
About the Charter Project Program
The Community and Charter Project programs provide a permanent, stable home for essential OSM tools and services.
Our Goal: We provide the necessary legal and fiscal frameworks so that developers and organizers can stop worrying about administration and focus on their true passion: building great things.
Applications to become a Charter Project are always open and are reviewed on a rolling basis.