Review:

The lovechild of a Mint Julep and Whiskey Sour, mint and bourbon sit together brilliantly in this simple sour.

Variant:

Maple Bourbon Smash
Whiskey Smash

History:

The modern-day notoriety and popularity of the Bourbon Smash is mainly thanks to Dale DeGroff featuring his riff on a Whiskey Cobbler (which called for two muddled orange wedges shaken with whiskey and sugar) in his 2008 book The Essential Cocktail. Dale's "Bourbon Smash" recipe is similar to above but calls for two muddled lemon wedges in place of the juice.

The first "Whiskey Smash" was published in the posthumously published 1887 Jerry Thomas' Bar-tenders Guide (Jerry "The Professor" Thomas died 15th December 1885) where it follows similar "Brandy Smash" and "Gin Smash" recipes. These "Smash" recipes omit citrus juice and are essentially Juleps. Indeed, the three "Smash" recipes follow six "Julep" recipes in the book.

Gin Smash.
(Use small bar-glass.)
Take 1 tea-spoonful of fine white sugar.
2 tea-spoonfuls of water.
1 wine-glass of gin.
3 or 4 sprigs of tender mint.
Put the mint in the glass, then the sugar and water. Mash the mint to extract the flavor, add the gin, and fill up the glass with shaved ice. Stir up well, and ornament with two or three fresh sprigs of mint.

Whiskey Smash.
(Use small bar-glass.)
Take 1 tea-spoonful of fine white sugar.
2 tea-spoonfuls of water.
3 or 4 sprigs of young mint.
1 wine-glass of whiskey.
Proceed, exactly, as directed in the last recipe.

Anonymous, Jerry Thomas' Bar-tenders Guide, 1887