Frequently Asked Questions
If you don't see what you're looking for here, feel free to get in touch.
Can I type in my address somewhere to search for maps of my house?
Not yet, though the pieces are in place for this to be implemented (just haven't had time). The best way to find a specific location is to
- Go to the Browse page and find your city on the map.
- Go to viewer for your city.
- Pan and zoom the map or use the "locate me" button to find your location.
See also: Using the Viewer
How accurate are these maps?
This is a more complex question than it may seem at first, but in general the original Sanborn maps were factually and spatially quite accurate (though not without errors), but the way they are georeferenced and presented as overlays on this site can be quite inaccurate.
This is because the ground control points created during the georeferencing process may not have been placed well, creating distortion or general misalignment of the maps. No attempt to calculate GCP error values has been made on this platform (yet).
That said, you'll quickly see that even with slight misalignment in some places, these maps still provide a rich window into the historical fabric of the city.
My city isn't on here, why not?
For now, the site only has maps that were included in the 2022 pilot project, which included a wide range of Sanborn editions across Louisiana. (We've added a few random ones since as well.)
What volumes were included in the pilot project?
To provide wide geographic and temporal coverage throughout Louisiana while also limiting the amount of disk space needed we devised the following criteria:
- Include the earliest edition for every community, regardless of date.
- Include any editions published through 1910 for all communities outside of New Orleans.
- Include only the earliest full coverage of New Orleans (in four volumes, from 1885 to 1893).
Applied across the state, these criteria produce 268 volumes covering 138 communities, with a combined sheet count of over 1,600.
How can I add more volumes?
We are open to adding more items from the Library of Congress collection on an ad hoc basic (especially for smaller cities and towns).
Please fill out this Google form to tell us what maps you are interested in.
If you or your organization would like to sponsor the addition of all Sanborn maps in your county or state we would love to discuss how to work with you, just get in touch.
Why are you using the term "volume"?
We are using this term somewhat imprecisely, because only Sanborn maps of large cities have proper "volumes" (see New Orleans 1885 vol. 1, 1885 vol. 2, 1887 vol. 3, and 1893 vol. 4). The vast majority of maps in the Sanborn collection may be better called "editions" (see Baton Rouge, 1885).
However, the hierarchy of the LOC collection handles editions and volumes at the same level, they are "items", so we decided "volume" would be a reasonable compromise for the sake of unity. Therefore, a volume is an atomic unit that contains one or more sheets. (No one has actually asked this yet,but just in case.)