During the prohibition era, many people became ill or even were killed due to poisonous home-made alcoholic mixtures known as "hooch" or "shine" (short for moonshine). A rumrunner/bootlegger named McCoy had a good three year run using a ship to import genuine alcohol to the united states, and became famous for carrying only the highest quality liquors. His cargo became referred to as the "Real McCoy", and the term became a common way of inquireing as to the authenticity of liquor products, and is commonly used today to inquire as to the authenticity of just about anything. McCoy was intercepted and arrested by the U.S. Coast Guard in 1923.
Is that the "real McCoy"?