Oldinsurancemaps.net is now a Charter Project
Ranked #1 on Hacker News with 49 points and 4 comments.
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