I think I saw some chickens at the Biltmore in NC the last time I was there. I'm almost sure you could ask them for eggs, if you want famous chickens. And if you offer them hatching egg prices you just might get a lot of eggs. It seems like the place is booming over there, new hotels, more ticket options, and of course the lovely gardens.
But as for chickens from the plantation of Thomas Jefferson, I'm thinking those are long gone. I could be wrong though. The historical society is able to trace down furniture and all kinds of other "valuable" junk when they restore historical homes. I suppose it is possible that some kind of chickens were kept and flock bred at the home over the years. Not the RIR though as others have pointed out, the dates are wrong for that to be true.