The mint julep is an alcoholic cocktail developed and popular in the southern United States. It has become the official drink of the Kentucky Derby, one of the world's most famous horse races. The drink traditionally has four ingredients: water, bourbon, sugar and mint.
Mint juleps can be served in a myriad of ways depending on the bartender. According to Wikipedia, the true history of the Mint Julep might never be fully known, but we do know a few things. The mint juleps originated in the southern United States, and the earliest mention came in 1803 when John Davis mentioned it in a book published in London.
From this we can surmise that the drink was probably around for at least a few years before the book was published, so it probably dates back to the 18th century. Henry Clay, a U.S. Senator from Kentucky brought the drink to Washington D.C. at the Willard Hotel while he lived in the city.
Churchill Downs, the venue at which the Kentucky Derby is held every spring, has been promoting the mint julep since 1938. Since the mid 1990s the official mint julep of the Derby has been made with Early Times Kentucky Whiskey. However, if you're willing to spend some serious cash, like $1,000, you can have a mint julep served in a gold plated cup with a silver straw, and made with Woodford Reserve, mint imported from Ireland, sugar from Australia and shaved ice from the Bavarian Alps. The proceeds go to charities that specialize in helping retired race horses.