Just found that they're manufactured in Hoenwald. Great small town. If you need a place for the first overnight, suggest Mousetail Landing SP. It's back west about 30 miles (?) on Hwy 412. Just before the bridge over the TN River is Hwy 438. Take a right and about 3 - 4 miles up is our favorite CG - go in the main entrance, not the first as it's primitive/boat lauch area. They aren't technically open for camping that time of the year, but if you can get your fresh water filled first, they have electric year round. It's about 45 miles from home and is always our first choice. If you want another option, Natchez Trace SP is about 20 miles further west, then north on Hwy 104 in Lexington. About 7 miles. Nice campsites with full hookups....don't know their water situation in the winter. Suggest if either of these might work, call the park directly for details. There is not much heading east from Hoenwald until you get into the Nashville area and they tend to be VERY pricey.
BTW, Hoenwald has a Elephant Sanctuary for abused or other elephants. I don't think they have any visiting, but there is an office on Hwy 412 right in town (there are only about 3 stoplights there) and if that is something that interests you, might make a great stop. They do wonderful work and are always in need of donations of any size. Worth a few minutes online.