Single malt whiskey isn't the first style you think of when it comes to American distilleries. With so many other options open to them, single malt whiskey hasn't been widely produced in the U.S.A.
There are always a few rebellious souls that want to do something different and have crafted single malt whiskey in the United States with some very intriguing results. With the cost and time involved in making single malt compared to bourbon, it will most likely never become a huge part of American whiskey distilling culture, but it is interesting to see what American distillers can do with this most traditionally Scottish style of whiskey.
The very fact that there even is American single malt whiskey, when they have several other styles to call their own, shows the passion and desire that the distillers in the U.S.A. have to create new and exciting things as a natural extension of the craft brewing explosion.