The Pittsburgh Photographic Library (PPL) is a photography repository held by the Carnegie Library of Pittsburgh of over 50,000 prints and negatives relating to history of Pittsburgh, Pennsylvania, United States. It is also the name of the core collection of roughly 18,000 photographs, which were taken from 1950-1953 as a documentation project headed by Roy Stryker, and which subsequently gave the current repository its name. The Library of Congress initially wanted to house PPL, but it was transferred to Carnegie Library of Pittsburgh in June 1960.