Free Library of Philadelphia Map Collection (Parkway Central)

The Free Library's Map Collection at Parkway Central includes extensive Sanborn fire insurance maps, city atlases, and municipal plats that record detailed lot lines, building footprints, and street configurations from the 19th and 20th centuries. These maps are commonly used to trace historical property surveys, urban growth, and alterations to Philadelphia's surveyed streets. The Map Collection is open to researchers seeking historical cartographic and survey information about the city.