Thank the people at the Great Mountain Forest Chestnut Research Orchard. They and a few other groups around the US are trying to bring this great American tree back. The American Chestnut was "technically extinct" by 1920 after a killer fungus blight. You can find out more at the American Chestnut Foundation https://www.acf.org/ . New survivable trees are being developed in these orchards through a long term cross pollination process. Darwin would be proud.