I have on my mantel a chestnut bur that a visitor picked up in the woods here - but he didn't remember where and I've never seen a live tree. Apparently occasionally a seedling does get large enough to bear before being dying from blight.
When I was a child, the woods were full of dead chestnuts - wonderful wood for fence rails since it split so easily. One of my chores was to split wood for kindling and it was a real pleasure to take an axe to a chunk of chestnut as it required barely an effort to split it into thin splints. But even 70 years ago, there were no living trees left.

At Museum Village (www.museumvillage.org) in Monroe they have the trunks of American Chestnuts used as columns in one of the buildings. I believe they were salvaged during the blight. There is also a small display about them. You can also go to http://www.acf.org to find out how these trees are being reintroduced.