Through the mid-1990s, librarians separated out photographs from each new collection that was donated to the archives into a distinct Photograph Collections. This process (sort by medium) made sense to the librarians working at the time. They gave each photograph an alpha-numeric P-number to identify the photograph by subject. The archives no longer organizes its photographs this way, keeping photographs within new collections in the original order or context that they were received. The original Photograph Collection, containing thousands of important images, still exists however, as decades of time and poor record-keeping have made it impossible to put these photographs back into the collections from whence they originated.