Jack Daniels is a whiskey because they filter it through charcoal to get rid of the bourbon flavour at least that's what the tour guide told me I too toured the distillery and would recommend doing so if your in Tennessee
The tour guide was wrong.
Jack Daniels IS a bourbon, according to both the legal definition of bourbon in the United States and according to the conventional definition of bourbon.
Charcoal filtering is something that is not done much outside of Tennessee, but charcoal flavoring does not make a bourbon no longer a bourbon. Just like adding vanilla to a beer doesn't make it no longer a beer. Charcoal filtering DOES add flavor, but it does not "get rid" of any flavor.
As a pretty big whiskey drinker, I'm quite familiar with different kinds of whiskey, especially bourbon as it is my favorite kind (and Gentleman Jack, which is twice charcoal filtered, is my favorite by JD). I also was in Tennessee just a few weeks ago and bought quite a few different Tennessee whiskeys. They are ALL bourbons.
It's mainly state pride that makes them call it Tennessee whiskey. As I said and as others have said, Jack Daniels meets every single legal requirement to be called a bourbon, which is:
1. It must be made within the United States. Jack Daniels meets this requirement. Although bourbon is most associated with Kentucky, it can be made in any state, including Hawaii, Alaska, Rhode Island, and so on. In fact, I bought some bourbon from a distillery up near San Francisco, California where I used to live. The guy there said "People from Kentucky will swear up and down that it's not bourbon if it's not from Kentucky or Tennessee. History and the law disagrees with them."
2. It must be made from at least 51% corn (in regards to the grain bill). Jack Daniels meets this requirement. You'll notice that Scottish (Scotch) and Irish whiskeys are primarily made from barley.
3. It must be aged in NEW CHARRED OAK barrels. Jack Daniels meets this requirement too. You'll also notice that Scottish (Scotch) and Irish whiskeys usually use USED oak barrels, some of them charred and some of them not charred (many of them bourbon barrels sent from the US). I have also heard of Scotch companies that used dark rum barrels from Central or South America.
4. It cannot be distilled to more than 80% ABV. Jack Daniels meets this requirement. Different kinds of whiskeys have different requirements for this.
5. It cannot be bottled at less than 40% ABV. Jack Daniels meets this requirement. Again, different kinds of whiskeys have different requirements for this.
Note, unlike most countries, there is no requirement for how long bourbon needs to be aged with the single exception of "straight bourbon" which needs to be aged for 2 years and must have the age written on the bottle if it is less than 4 years old.
If your whiskey meets all 5 of the requirements above, it is bourbon regardless of whether you filter it through charcoal, filter it through hops, filter it through moss, or whatever you want to do.
Therefore, Jack Daniels is bourbon by every definition possible. Tennessee folks just don't like the association that bourbon has with Kentucky, so they demand on calling it Tennessee whiskey... which is just another name for "bourbon from Tennessee."