David Nicholson Reserve is a sourced bourbon, though as a brand it has a long history that supposedly extends back to 1843. The story as it’s told is that David Nicholson was a grocer who started to distill his own whiskey in 1843, but as Chuck points out it it’s far more likely he was a blender than a distiller.
The signature whiskey, David Nicholson 1843, was around before prohibition and after prohibition it was made by Stitzel-Weller. Thought it was not one of their more widely known brands due to its limited distribution which has historically been around St.Louis and today is still mostly within Missouri and Illinois.
The traditional DN 1843 was, and still is, a wheater but this David Nicholson Reserve, a new addition to the line, is a sourced bourbon using rye as its secondary grain. Wheated and now traditional, if they add a high-rye to the line-up they’ll complete the bourbon trifecta.