I wouldn't say bison have been 'reintroduced' to Kentucky. They're in enclosures. They aren't allowed to roam, unlike the elk, which even have a hunting season.
When I was a kid there was a buffalo (bison) farm about 3 miles west of here in South Bend, IN, and another one about 15 miles to the north of us in Michigan. They raised them for meat. There's still a bison farm about 50 miles to our southwest. I'm sure there are probably bison in just about every state. But they don't run free anywhere east of the Mississippi river as far as I know.