Mapping Philadelphia History: How geographic technologies enhance access to digitized archival collections

Philadelphia’s City Archives, managed by the City’s Department of Records (DoR), contains an estimated 2 million photographs, some dating as far back as the 1860s. Photographers assigned to City departments such as the Departments of Streets, City Transit, and Public Works originally took these photographs to document public works projects. Now they provide a rich photographic record of the City’s growth and development.

The DoR is digitizing these photographs and making them available to the public via PhillyHistory.org. The key feature of PhillyHistory, setting it apart from other digitized archival collections, is that geography is at the center of the project. Each digitized image is geocoded as it is uploaded to the system, enabling site visitors to search and display images based on location as well as more traditional options such as date and keyword. New images are regularly added to the site (at a rate of about 2,000 per month), and users can save searches and subscribe to RSS feeds for updates on the latest photos of their favorite locations. GeoRSS enables users to display recently updated images in GoogleMaps, and the first 100 results of any search can be mapped in Google Earth. Users can share images with friends, a mobile edition literally brings PhillyHistory’s resources to the man on the street, and an e-commerce module facilitates purchase of print copies of the images.

This presentation will focus on how the geographic approach has spurred PhillyHistory’s growth into an invaluable asset for the Department and a beloved site for users. It will chronicle how the project came to incorporate such a broad range of technologies, what future directions it hopes to take, and how it fits into the expanding world of georeferenced photography.