the real McCoy

"The real McCoy" is an idiom and metaphor used in much of the English-speaking world to mean "the real thing" or "the genuine article", e.g. "he's the real McCoy". The phrase has been the subject of numerous false etymologies. History The phrase "The real McCoy" may be a corruption of the Scots "The real MacKay", first recorded in 1856 as: "A drappie o' the real MacKay" ("a drop of the real MacKay"). This appeared in a poem Deil's Hallowe'en published in Glasgow and is widely accepted as the phrase's origin. A letter written by the Scottish author Robert Louis Stevenson in 1883 contains the phrase, "He’s the real Mackay". In 1935, New Zealand mystery writer Ngaio Marsh presented a character in Enter a Murderer who muses whether gun cartridges used in a play were "the real Mackay."<ref>Ngaio Marsh: A Man Lay Dead, Enter a Murderer, The Nursing Home Mystery p. 262 Harper London UK (2009)</ref> In 1881, the expression was used in James S. Bond's The Rise and Fall of the 'Union Club'; Or, Boy Life in Canada. A character says, "By jingo! yes; so it will be. It's the 'real McCoy,' as Jim Hicks says. Nobody but a devil can find us there." The expression has also been associated with Elijah McCoy's oil-drip cup invention, patented in 1872. One theory is that railroad engineers looking to avoid inferior copies would request it by name, inquiring if a locomotive was fitted with 'the real McCoy system". This possible origin is mentioned in Elijah McCoy's biography at the National Inventors Hall of Fame. The original appearance of this claim in print can be traced to an advertisement which appeared in the December 1966 issue of Ebony. The ad, for Old Taylor Bourbon whiskey, ends with the tag line: "...but the most famous legacy McCoy left his country was his name."