"One of the oldest historical societies in the United States," the Historical Society of Pennsylvania was founded in 1824. Designed by Addison Hutton, the Historical Society of Pennsylvania's building is listed on the City of Philadelphia's Register of Historical Places. Known for its 17th, 18th and 19th century holdings, it contains one of the largest family history libraries in the nation with around 600,000 printed items and over 19 million manuscript and graphic items.