American whiskey is taking over the world.Vodka still has the biggest market share of the three big hard liquors in the US, but growth in whiskey is booming rapidly catching up.Vodka sales, by volume, were up 1.6% in 2014. Tennessee whiskey and bourbon sales by volume were up 7.4% in the same period, according to the Distilled Spirits Council, the industry's trade association.And when it comes to exports, all people really want is American whiskey.Here's a chart from the DSC:People in the US and abroad are developing a greater taste for whiskey, but the exports also has to do with the weird naming rules that whiskey has. For instance, Champagne can only technically be made in the French region of Champagne, bourbon can only be made in the US. It's the same with Scotch in Scotland and Irish whiskey in Ireland.Each of those kinds of whiskeys are made a little bit differently and have a relatively distinctive taste. At least that's what their producers will tell you. So there's less supply of each kind. As people around the world develop a taste for American whiskey, they have to import it from the US.Vodka and rum, on the other hand, can be made anywhere in the world. They may taste a little bit different, but so far American producers haven't convinced the rest of the world that our spirits other than whiskey are really worth importing.Figuring out how to convince people of that is potentially worth billions.Join the conversation about this storyNOW WATCH: What Makes Vintage Whiskeys Worth Thousands Of Dollars Click here to read full news..