Sanborn Fire Insurance maps newly available online through University Libraries

This engineering drawing of Franklin Square in Philadelphia is part of the Sanborn Fire Insurance Maps of 1925 collection, which became part of the public domain on Jan. 1, 2021, and is now freely available for use through Penn State University Libraries’ Donald W. Hamer Center for Maps and Geospatial Information. Credit: Donald W. Hamer Center for Maps and Geospatial Information All Rights Reserved.

UNIVERSITY PARK, Pa. — As of Jan. 1, materials published or copyrighted in 1925 became part of the public domain and are now freely available for use. Among the most anticipated collections of such materials in the Penn State University Libraries are the Pennsylvania Sanborn Fire Insurance Maps of 1925, a collection of maps of 69 towns consisting of 1,600 individual map sheets, most notably four volumes each of Philadelphia and Pittsburgh.

These maps joined 1,100 sheets depicting 40 towns published in 1924 that came out of copyright Jan. 1, 2020, as well as thousands of other maps of Pennsylvania cities and towns from 1884 to 1923 that were already in the public domain.

“The Sanborn collection is the most used digital collection maintained by Penn State University Libraries because of the wealth of detailed and accurate historical information the maps contain about people and places,” said Nathan Piekielek, geospatial services librarian in the University Libraries’ Donald W. Hamer Center for Maps and Geospatial Information.

The Sanborn Fire Insurance Map Company made and sold maps — or, more accurately, detailed engineering drawings — of populated and industrial areas in the United States from 1867 through the 1990s to help insurance companies assess risk of fire loss. Based on extensive field survey and measurement, they were typically drawn at a scale showing a precise level of detail for approximately 12 square blocks. The maps showed building shape, height and construction materials; land uses and building occupants; and locations and names of streets, water lines, fire hydrants and utilities. Many cities and towns were mapped as many as seven times by the Sanborn Map Company, showing change through time. 

“Sanborn maps provide consistent snapshots of American community development from the Industrial Age through the Great Depression and into the years following World War II — some would say the most important and formative years of our nation’s recent history,” Piekielek said. 

Contemporary uses of Sanborn maps include historic preservation, zoning, genealogy, industrial archeology and environmental assessment. The maps are also appreciated by map enthusiasts.

With more than 30,000 map sheets, the University Libraries has a nearly complete collection of Sanborn maps for cities and towns in Pennsylvania from 1884 through the mid 1950s. The collection is one of the largest outside the Library of Congress. 

For information about the Sanborn maps, contact the Donald W. Hamer Center for Maps and Geospatial Information, a unit of the department of Research Informatics and Publishing at Penn State University Libraries.

Last Updated January 21, 2021