I say it's not. It's labeled a Tennessee whiskey, but technically according to the law, it's a corn whiskey, since it is made form 80% corn. I suppose one could argue a grey area in that the legal definition says a bourbon must be at least 51% corn, but states no upper limit, until you get to the next section defining corm whiskey, where it states the 80% requirement. Also, JD is charcoal filtered, which is something almost never done (can't name one that does, actually) to bourbons.

Other than those two items, it fits the description of a true bourbon.