The New Castle Historical Society is devoted to preserving local history, from the time of the Mahican nation to the Quaker settlement, to the building of the Greeley country estate in 1852 and up through the present. Today the Horace Greeley House is a central part of Chappaqua and serves as a pleasant reminder of times past. 

The museum holds exhibits that are open to the public throughout the week. There is also a charming shop on location that offers a variety of wares, such as tea pots, afghans, scarves and note cards among other gift items.