Following a merger with the Balch Institute for Ethnic Studies, this superlative special-collections library now contains more than 500,000 books, 300,000 graphic works, and 19 million manuscript items; the emphasis is on Colonial, early national, and Pennsylvania history, as well as immigration history and ethnicity. Founded in 1824, the society also owns one of the largest family history libraries in the nation. This is the place to go to trace your family roots. Notable items from the collection include the Penn family archives, President James Buchanan's papers, a printer's proof of the Declaration of Independence, and the first draft of the Constitution. The library is open to anyone over 13 years old.