E.I.s first success in America, black powder.  At Eleutherian Mills we toured the first du Pont home, modest compared to many other of their mansions one can tour.  The house was cool to see but the best part of the site is the manufacturing grounds tour.  Restored equipment and working models demonstrate the making of black powder from refining sulfur and potassium nitrate to the oh-so-touchy mixing process.

There are some great examples of waterwheels and turbines and a working belt driven machine shop. It is admittedly a bit nerdy but a fun stop.

Another bonus, it is on beautiful grounds along Brandywine Creek that has been protected from sure development had this not been set aside as an historic site. It is a lovely place for a stroll.