Bourbon whiskey is a type of American whiskey, a barrel-aged distilled spirit made primarily from corn. The name derives from the French Bourbon dynasty, although the precise inspiration for the whiskey's name is unsettled; contenders include Bourbon County in Kentucky and Bourbon Street in New Orleans. Bourbon has been distilled since the 18th century. The use of the term "bourbon" for the whiskey has been traced to the 1820s, and the term began to be used consistently in Kentucky in the 1870s. While bourbon may be made anywhere in the United States, it is strongly associated with the American South, and with Kentucky in particular. As of 2014, the distillers' wholesale market revenue for bourbon sold within the U.S. is about $2.7 billion, and bourbon makes up about two-thirds of the $1.6 billion of U.S. exports of distilled spirits.