The Historical Society of Pennsylvania is a historical society founded in 1824 and based in Philadelphia. The Society's building, designed by Addison Hutton and listed on Philadelphia's Register of Historical Places, houses some 600,000 printed items and over 19 million manuscript and graphic items. The Society maintains printed collections on Pennsylvania and regional history and manuscript collections covering 17th-, 18th-, and 19th-century history. The holdings of the Balch Institute for Ethnic Studies were added in 2002 and those of the Genealogical Society of Pennsylvania in 2006. The Historical Society has recently undertaken efforts to appeal to a younger demographic, including having open bar events.