I worked in the booze business for many years although I've been away from it for almost 20 years. Maybe something changed in those years?
As I recall,
Heaven Hill, Evan Williams and Elijah Craig are all the same whiskey. The age length is what varies. Bourbon must be aged 3 years minimum by law. That's probably all that Heaven Hill gets. Evan Williams used to be sold as an 8 year Bourbon in Pa. only, and 7 years everywhere else. I believe that brand is down graded to a 4 year, today. The Elijah Craig label was brought out in the late 90's and is a 12 year Bourbon. The old 7 or 8 year Evan Williams WAS one of the best Bourbons for bargain money you could buy.
Jack Daniels was not legally a Bourbon. It and Geo. Dickel were in a legal category of "Straight Tennessee Whiskey". Not long ago, the state of Tennessee established rules on whiskey made there. They adopted many of the legal requirements of Bourbon. Like a min. of 51% corn in the mash and charred barrels. Also the charcoal filtering prior to barreling that most Bourbons didn't use.
Bourbon was fading away by the mid 80's, but diehards had every bar and restaurant regularly buying it. Scotch was in much worse shape for sales at the time. It was an accepted prediction in the 80's that the last living Scotch drinker (in the US) would be gone in 15 or 20 years. Single Malts were discovered by younger drinkers and saved the whole Scotch market. Unfortunately all the standard brands went along for 200 % or more price increases. Working man Scotch was dead. There were a couple of "ringer" labels that were quality blended Scotch, bottled here and sold very reasonably. All gone.
Booze trends and fads come and go away, usually gradually. Abut every 8 or ten years it goes on to or back to, something else. Micro, pardon me, craft beers are back for the third time and much more popular than other era's. Some fantastic brew being made ( and fantastic prices), but they will slide again.