From the Wikipedia page 
The Historical Society of Western Pennsylvania (HSWP) is a cultural organization in Pittsburgh, Pennsylvania. After several attempts during the early and mid-century to establish a historical society, an organization called Old Residents of Pittsburgh and Western Pennsylvania was formed on January 10, 1859. Five years later the group changed its name to Historical Society of Western Pennsylvania.
Now the region's oldest cultural organization, HSWP does business as and operates both the Senator John Heinz History Center and the Meadowcroft Rockshelter.
The History Center includes the Library & Archives, which preserves hundreds of thousands of books, manuscripts, photographs, maps, atlases, newspapers, films and recordings documenting over 250 years of life in the region; and the Western Pennsylvania Sports Museum, a museum-within-a-museum documenting Pittsburgh’s extensive sports legacy.
The History Center opened in 1996 in Pittsburgh's Strip District and receives funding from various private, foundation and governmental sources as well as public sources including the Allegheny Regional Asset District. There is a $10.00 fee to access the library/reference area on the 6th floor.