The PPS Research Library makes numerous books and periodicals on historic preservation available to the public. Our library holdings focus chiefly on the history and development of the city of Providence and its historic buildings. Resources include city directories dating back to 1824, historical maps, preservation planning documents, resources on preservation treatments and standards, copies of National Register documentation for properties in the city, periodicals, and the Gowdey Files Database, which includes historical information on buildings throughout Providence. The photo archives include slides as well as some prints of historic buildings throughout the City. Slides date primarily from the 1970s through the present day and are catalogued alphanumerically by street address.