Commentary BOURBON COUNTY, Ky.—About 250 years ago, farmers looking for a way to make their surplus corn crop profitable decided to distill it. Today, that leftover grain has become a billion-dollar industry and a symbol of the Bluegrass State’s identity, economy, and culture. “How bourbon came about is (what) … the American spirit looks like: business, independence, freedom, a little bit of luck, and a lot of perseverance,” said Justin Thompson. Thompson and his colleague Justin Sloan are the proprietors of The House of Bourbon, the world’s largest bourbon store, located on West Main Street in Lexington right across from Mary Todd Lincoln’s childhood home. And right now, business is booming. Thompson and Sloan started collecting rare and vintage bottles of bourbon 20 years ago, when the drink was out of favor. Then, four years ago, the state passed a law allowing the resale of distilled spirits and the duo …