Chances are you’ve heard the phrase “the real McCoy.” It derives from William McCoy, one of Prohibition’s most famous illicit importers of booze. (I’d say “rum runner” except that he also dealt in whiskey.) McCoy carried out his business by sea, first loading his cargo at Nassau in the Bahamas, then conveying it to the U.S. coast, initially in a vessel called the Henry L. Marshall and, as he grew wealthy, adding a second vessel, the Tomoka. The booze he brought into the United States became known as “the Real McCoy” because unlike other bootleggers, McCoy never diluted or adulterated it. In some circles, this made him a folk hero, but it did not impress Mabel Walker Willebrandt, the assistant attorney general charged with enforcing Prohibition and deadly serious about her job. She set her sights on McCoy and never wavered in her determination to bring him to justice. McCoy began his career as a nautical bootlegger in early 1920, shortly after the ratification of the Eightee...