Researching historic homes using Sanborn maps
- Mark Belloni
- Jan 30
- 3 min read
Updated: Feb 7
An incredibly valuable (and fun to use!) source available to historians researching historic homes are Sanborn maps. First printed in the 1860s and continuing well into the 20th century, the primary purpose of the maps was to help fire insurance companies assess risk in urban areas. Today, they now serve as unique historical records, offering details on property boundaries, building footprints, window and door layouts, construction materials, and the placement of outbuildings.
If your house appears on a Sanborn map, consider yourself lucky—not everyone has access to such a detailed source for researching their historic home. Because these maps were created for fire insurance purposes, they generally are only available for cities and larger towns. If you own a historic home in a rural area, you probably won't find it documented in a Sanborn map.
To illustrate their value, let’s look at the house at 98 West Broadway Street in Danville, Indiana, known historically as the Moses Keeney House. In 2019, the Hendricks County Historical Museum purchased the home. There was speculation that the house had not always been positioned as it is today, so the museum conducted research to determine its original orientation. Fortunately, Sanborn maps provided a clear answer.
Tax records suggest the house was likely built before 1846, though its heavily altered exterior makes this difficult to discern. The earliest available Sanborn map for Danville, from 1886, shows the one-and-a-half-story frame dwelling facing east on the corner of Jefferson and South (now Broadway) Streets.
The maps show this same orientation through the 1909 editions, but by the 1920 Sanborn map, the house has been rotated to face south—the position it occupies today.
These maps tell us that at some point between the years 1909 and 1920, the house at 98 West Broadway was rotated from facing east to facing south. Historical Danville newspapers can be consulted to reveal that a previous owner, Dr. Bridges, was responsible for moving the home:
Additionally, Sanborn maps can be used alongside historic photographs to help identify structures. While no known historical photographs directly depicting the house at 98 West Broadway, one image provides a clue about its original orientation. A 1908 postcard from the Hendricks County Historical Museum’s collection shows the former Hendricks County Sheriff’s residence, located just east of the house. In the bottom left corner of the photograph, a roofline is visible. By comparing this image to the 1907 Sanborn map of Danville, it becomes clear that the vantage point of the photograph captured the roofline of the Keeney house, offering further evidence of its past alignment.
Sanborn maps are invaluable tools for researching historic properties, offering detailed insights into a building’s location, orientation, materials, and surrounding structures over time. In the case of the Moses Keeney house at 98 West Broadway, the maps provided crucial evidence that confirmed the home’s original east-facing orientation before it was rotated to its current position. When combined with other sources, such as historic newspapers and photographs, Sanborn maps can help piece together a property's history in ways that might otherwise be impossible.
