The name derives from Bourbon County, Kentucky, which was itself named after the French royal family at the time of the American Revolutionary War. Some stories about its origins there are not true, such as its purported invention by Baptist minister and distiller Elijah Craig, whose distillery was located in what was then part of Bourbon county (though subsequent division of the county has left only a much smaller Bourbon county today...which is "dry" and has no distilleries). The first whiskey distilled in America was actually made in 1621 by George Thorpe, an Episcopal minister, at Berkeley Plantation in Virginia.
A further refinement introduced by Scottish chemist Dr. James C. Crow was the sour mash process, by which each new fermentation is conditioned with some amount of spent beer (previously fermented mash that has been separated from its alcohol), in much the same way that sourdough bread is made from starter. The acid introduced by using the sour mash controls the growth of bacteria that could taint the whiskey. As of 2003, all straight bourbons use a sour mash process. Crow developed this refinement while working at the Old Oscar Pepper Distillery (now the Labrot & Graham Distilllery) in Woodford County, Kentucky. A concurrent resolution passed by the United States Congress in 1964 restricted bourbon to U.S. production.
As of 2003, bourbon is made in Kentucky, Indiana, Georgia, and Virginia. However, most bourbon lovers consider the whiskey made in Kentucky to be the best in quality. Curiously, when thinking about bourbon, many people first think of the brand Jack Daniel's, which is of the similar Tennessee style, and not technically a bourbon.