About the Historical Society
Premier research library and museum for Pennsylvania history. Features extensive manuscript collections, rare books, and artifacts documenting Pennsylvania from William Penn through industrial revolution and modern times.
One of America's Most Comprehensive Research Collections
Founded in 1824, the Historical Society of Pennsylvania stands as one of the nation's largest non-governmental repositories of documentary materials. The collection comprises approximately 600,000 books, pamphlets, serials, and microfilm reels; 20 million manuscripts; and over 300,000 graphics items including photographs, postcards, sheet music, menus, and trade cards. Among its national treasures are the first two drafts of the United States Constitution, an original printer's proof of the Declaration of Independence, and the earliest surviving American photograph. While the collections primarily focus on Philadelphia, Eastern Pennsylvania, and the greater Delaware Valley, they also encompass materials from across the eastern United States and international sources.
Preserving Black American History: The Leon Gardner Collection
In December 2025, HSP received a prestigious Save America's Treasures grant to preserve the Leon Gardner Collection of American Negro Historical Society Records (1715-1962). This vital 8.9 linear foot collection contains manuscripts, publications, and ephemera saved by the American Negro Historical Society, founded in Philadelphia in 1897. The materials illuminate Black life, leadership, education, and culture across nearly two and a half centuries, making it one of the most significant archival collections documenting Black American history. This conservation project ensures these irreplaceable materials will remain accessible to researchers and the public for generations to come.
Research Services and Educational Partnerships
HSP serves thousands of on-site researchers annually and millions more through its digital collections online. Manuscript collections include personal papers from individuals and families, as well as organizational and business records spanning the seventeenth through twenty-first centuries. The society offers public programs, workshops, and special exhibitions throughout the year featuring notable historians, authors, and archaeologists. Through a teaching alliance with the University of Pennsylvania's Kislak Center for Special Collections, HSP provides curatorial assistance and archival research opportunities to Penn faculty and students, ensuring the next generation of historians can engage directly with primary source materials that shaped American history.
Plan Your Visit
The Historical Society of Pennsylvania's special collections library at 1300 Locust Street is open to the public Tuesday through Friday. Researchers are encouraged to contact Visitor Services at (215) 732-6200 ext. 221 or sduda@hsp.org in advance. If taking the PATCO train from Southern New Jersey, exit at the 13th & Locust stop—HSP is located on the southwest corner. Many collections are also available through HSP's Digital Library online.
Getting Involved
Support HSP's mission to inspire people to create a better future through historical understanding. Become a member, make a donation, or contribute historical materials related to Philadelphia, Eastern Pennsylvania, and the greater Delaware Valley. The society welcomes manuscripts, photographs, and artifacts that help document the region's rich heritage.
Explore Pennsylvania's Historical Landscape
Use the When It Was app to discover historical businesses, landmarks, and buildings throughout Pennsylvania. See how your community has transformed over the decades.
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