Researching historic homes using Sanborn maps

Sanborn maps are incredibly valuable sources available to anyone researching historic homes. First printed in the 1860s and continuing well into the 20th century, the primary purpose of these maps was to help fire insurance companies assess risk in urban areas.

No longer used for their original purpose, Sanborn maps today serve as unique historical records, offering details pertaining to property boundaries, building footprints, window and door layouts, construction materials, and the placement of outbuildings.

Because these maps were created for fire insurance purposes, they are generally only available for cities and larger towns. Therefore, homes in rural areas are unlikely to be documented in Sanborn maps.

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. Sanborn maps helped provide 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 west on the corner of Jefferson and South (now Broadway) Streets.

Snippet from 1886 Sanborn map of Danville showing the Moses Keeney house facing east on the corner of Jefferson and South (now Broadway) Streets. Indiana University - DataCORE.

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.

Snippet from 1920 Sanborn map of Danville showing the the Moses Keeney house facing south on the corner of Jefferson and Broadway Streets with a new home constructed to its east. Indiana University - DataCORE.

These maps tell us that at some point between the years 1909 and 1920, the house at 98 West Broadway was rotated from facing west to facing south. Historical Danville newspapers can be consulted to reveal that a previous owner was responsible for moving the home:

The Republican, May 25, 1916. Newspaperarchive.com

The Republican. August 31, 1916. Newspaperarchive.com

Additionally, Sanborn maps can be used alongside historic photographs to help build evidence. While no known historical photographs directly depict the house at 98 West Broadway, one photograph provides a clue about its original orientation.

A 1908 postcard shows the former Hendricks County Sheriff’s residence, located just east of the Moses Keeney house. In the bottom left corner of the photograph, a roofline is just barely 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.

Hendricks County’s Sheriff’s residence, c. 1908. Hendricks County Museum Digital Collections. Examining the photo closely reveals the roof of the Keeney house in the bottom left.

1907 map of Danville. The green arrow represents the vantage point of the photograph taken in 1908, capturing the roof of the Keeney house directly behind the Sheriff’s residence. Indiana University - DataCORE.

Conclusion

As outlined in this blog, 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, the maps provided crucial evidence that confirmed the home’s original west-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 more meaningful and detailed ways.