American Philosophical Society Philosophical Hall

Philosophical Hall is a modest two-story brick building with symmetrical facades, identified by its Federal-style architecture and delicate fanlights. It stands on the eastern side of Independence Square as the only privately owned structure in the park. Built between seventeen eighty-five and seventeen eighty-nine, it serves as the headquarters for the American Philosophical Society, the oldest learned society in the United States. Benjamin Franklin founded the organization in seventeen forty-three to promote useful knowledge, and it has maintained this location as its primary home for over two centuries.