American Philosophical Society. Click on picture for bigger view.

This structure, dated 1789, is the only private building in Independence Square. Founded in 1743 by Benjamin Franklin, "The American Philosophical Society held at Philadelphia for promoting useful knowledge", is not only the oldest organization of its kind in the country, but is one of the most distinguished scientific and intellectual societies in the world.

Original Members of the Pennsylvania Cincinnati who were elected members:

Notable members from other State Societies of The Cincinnati:

• Thaddeus Kosciusko
• Gilbert du Motier, Marquis de La Fayette
• Frederick William, Baron von Steuben
• George Washington

The society's original building and its new Library are both open to the public.