THe death of the American Chestnut and the extinction of the Passenger Pigeons are not linked. This extensive article on their demise says that their prime food was acorns and beechnuts. Pigeons were well on their way out decades before 1904, and it was people and the railroads that did it according to this:
https://www.audubon.org/magazine/may-june-2014/why-passenger-pigeon-went-extinct
Another aspect that I read a while ago is that they needed a flock of a certain size to stimulate their breeding hormones. By the time they only had a few specimens left, they could no longer promote breeding. If they try to restore the PP, they will have to build a big enough flock to create that stimulus. A major task.
This link from the American Chestnut Foundation answers many questions: http://www.acf.org/Q&A.php
Here is one commercial source that claims resistance. Unfortunately, they only deliver to some states. However they have extensive material on how, when, where to grow them, diseases, etc.: http://www.chestnuthilltreefarm.com/?gclid=CN_EjMvp28cCFUcXHwodxvMAGg
This Georgia based company mentions no restrictions on shipping: https://www.willisorchards.com/product/american-chestnut-tree#.VejBEflVikp
The impression I get is that while there might not be certified resistant Chestnut trees, you can manage to grow them, especially if your soil is not already infected. The grow quickly and start producing early and are not extinct, merely rare in the wild.
They used to roost and mate in eastern Michigan (among probably other places); their carcasses were in big demand as the primary source of squab, and they just sat on the branches making sounds. Mowing them down with shot was a way of earning a living (probably a kind of poor one) and recovery of the species was difficult because lumbering cleaned out nearly the entire state before 1920 (the last big old-growth tree around here was about three or four miles west, and was cut before US involvement in WWI).