The people of Tennessee are very passionate about the whiskey they make. Although very similar to bourbon there are a few differences that set it apart.
The most obvious of these is that it must be made in the great state of Tennessee itself. The second is that it is filtered through maple charcoal before being laid down in a cask. This charcoal filtration in Tennessee is known as the 'Lincoln County Process' and gives the whiskey a smoother feel and ashy texture. It is not a legal obligation to filter the whiskey in this way but in many senses it has become synonymous with Tennessee whiskey. The name comes from Lincoln County, which was the site of the original Jack Daniels distillery where the method was employed. As it happens, over the years the county lines have been re-drawn and currently there are no distilleries within Lincoln County itself.
Although there are not many brands of Tennessee whiskey it does have some very well known whiskies. The most obvious being Jack Daniels, which is one of the biggest and most well known spirits in the world. So next time you order a 'Jack and Coke' and can smile to yourself knowing it's not quite the same as a standard 'bourbon and coke'.