The Historical Society of Pennsylvania
"Founded in 1824 in Philadelphia, The Historical Society of Pennsylvania is one of the oldest historical societies in the United States and holds many national treasures. The Society's building, designed by Addison Hutton and listed on the City of Philadelphia's Register of Historical Places, houses some 600,000 printed items and over 19 million manuscript and graphic items." The Society's library is one of the preeminent libraries in the nation, housing extensive manuscript collections from the 17th, 18th and 19th centuries. Finally, the Historical Society has paired with Genealogical Society of Pennsylvania through a Strategic Alliance Agreement, and the Society has become "a chief center for the documentation and study of the ethnic communities and immigrant experiences."
The site offers an online catalog, 10 online manuscript collections, an online event calendar, exhibit information along with nine online exhibits, purchasing information for the society's publications, and educational resources, including lesson plans, readings, primary sources, online exhibits, and information on educational workshops.