Where did the expression "The Real McCoy" come from?

Television show back in the late 50s and early 60s?

l once thought it had something to do with the Hatfield-McCoy feud.
http://en.wikipedia.org/wiki/Hatfield-McCoy_feud

But this is what trusty old Wikipedia had to say.
http://en.wikipedia.org/wiki/The_real_McCoy

The expression was common before the television show of the same name was popular. I think the star of that show was Walter Brennan.

Elijah McCoy invented the steam engine way back when. Others made inferior ones, or something, so people exclaimed that they weren’t “the real McCoy.”
I was in a musical in fourth grade called “Use Your Imagionation” in which we sang about inventors, and this was one song:)

I heard (on the history channel) That during the prohibition era there was a manufacturer or it might have been a smuggler who consistently delivered quality alcohol to the underground alcohol clubs while everyone else was making god awful brews that needed to be mixed with other things. The manufacturer/smuggler’s name was mccoy

actually this says that it isn’t clear where the expression came from

@jaketheripper I’m positive about Elijah McCoy. It doesn’t say it on the wikipedia page for the man, but writers of a children’s musical wouldn’t spread false information:)

@jaketheripper Thats what wikipedia says but how do we know if its true or not? I would recommend getting more sources instead of just trusting wikipedia. @raylrodr The Black Inventors Museum, a much more credible source in my opinion, explains the expression in paragraph 5 on its website.

@Ailia In case you didn’t know wikipedia does cite other much more “credible” sites like this. Everywhere you look on line says it’s not known precisely where the phrase came from. But hey if were going for credibility Time Magazine says I’m right.

@jaketheripper Thats what Time Magazine says but it does not say specifically that’s where the expression came from. Unless you can find a credible source saying that the expression came solely from that, I don’t believe it.

@Ailia the article you directed us to doesn’t clearly say that the story of Elijah McCoy is the sole origin of that expression. What I’m saying is that clearly the answer is nebulous there are many explanations each with documentation and history to go along with. I can’t say with certainty where it came from and I don’t think you can either.

@jaketheripper Well if you want to leave it at that then I’m perfectly okay with doing that. I think @raylrodr has attained enough information to know that this expression is fairly elusive in terms of its orgins. So whether it was Elijah McCoy or William McCoy or both, I don’t think it really matters. The expression still stands.

Here you go. Scholastic really wouldn’t spread false information.

William (Bill) McCoy was a bootlegger on the Atlantic coast of Florida well known for selling quality imported goods: the original “real McCoy.” http://www2.potsdam.edu/hansondj/FunFacts/Prohibition.html