Have you ever used an expression or idiom and then taken a moment to actually listen to what you just said? And then noticed that, hey, I have no idea where the hell that expression comes from? I feel like I do that a lot. Or, alternately, I’m just simply wrong about the origin of some expressions. For example, I always sort of assumed “look a gift horse in the mouth” had something to do with the Trojan Horse, a very famous gifted horse. Of sorts. But it has nothing to do with that. It has to do with actual, literal horse mouths and the damp horse teeth within.
This recently happened to me with another expression, when things are referred to as “the real McCoy,” but this time I was just ignorant, not wrong, and was happily surprised to find that the origin of the expression happened to have something to do with mechanized transportation systems, which means I can use it as something to write about here on this very site. And, even better, it’s all thanks to a Black inventor, and it’s still Black History Month, which means it’s even sort of timely, or at least as timely as something 154 years old can be.
The inventor was a man named Elijah McCoy, and the invention was one of the first automatic oiler mechanisms for locomotives. You see, the early steam engines that powered railroad locomotives lacked any sort of automatic lubrication systems. This meant that on almost any journey by train, stops would have to be factored in to allow engineers the chance to lubricate all of the moving components of the engine so that friction wouldn’t cause everything to just melt into a huge smoldering pile of iron slag. The usual distance that a train could travel between stops for inspecting and oiling bearing surfaces was right around 100 miles. So, if we assume that train speeds of that era were around 30 mph, then we’re talking stopping the entire train every three hours. Given the distances of rail travel, especially in America, this is an awful lot of stopping, which meant longer travel times and a loss of time and money for everyone.

As you can imagine, a system that oiled these complex machines automatically, without requiring regular stops, was a very big deal.
Before we get into the details of the oiling system that would eventually bear his name, it’s worth recounting a bit of Elijah McCoy’s early life, because it’s an interesting journey. He was born to parents who escaped slavery in Kentucky via that famous metaphorical railroad, the underground one. They escaped to Ontario, Canada, where little Elijah was born. In return for enlisting in the British army, his father received a land grant.
Eventually, his family made it back to the United States, settling in Ypsilanti, Michigan, where he found himself fascinated by machinery. He was able to go to engineering school in Edinburgh, Scotland, and when he returned, he got a job working for the Michigan Central Railroad.
At that time, the railroad did not allow Black people to be engineers, so McCoy got a job as a fireman and lubricator, which was hot, sweaty, difficult work that put him in very direct and protracted contact with the workings of the locomotive. It was during this period that the need for some sort of automatic lubrication system became apparent to McCoy, and so he applied his considerable intellect to the problem.

In 1872, he came up with an ingenious solution that used the steam pressure of the engine to help deliver the oil to where it was needed. Here’s how the patent describes the mechanism, illustrated above:
A represents the oil-cup, provided with the cover B. In the center of the bottom of the cup A is a downward-projecting stem, 0, to be screwed into the place where the lubricator is to be used. This stem is hollow, and from the same extends a tube, D, through the center of the cup. Within this tube is a rod, 1, having a valve, b, at its upper end above the tube D to close the same, and at the lower end is a piston or disk, d, within the stem 0. Around the lower end of the rod a, between the piston d and a shoulder in the stem, is placed a spiral spring, a, which forces the rod down, so that the valve b will close the upper end of the tube D and prevent the passage of the oil.When the steam presses upon the piston the valve rises and allows the oil or other lubricating material used to pass out.In the cover B is a thumb-screw, E, directly above the valve 1), by means of which the flow of oil may be readily regulated. At the bottom of the oil-cup is a faucet, G, for the purpose of drawing oil the condensed steam when necessary.


The widespread demand for such an automatic oiler and the relative simplicity of the design not only meant widespread acceptance, but also widespread copying of McCoy’s basic design. Knockoff automatic oiling mechanisms were rampant, but the original Elijah McCoy design was so much better than these Victorian-Era-Temu knockoffs that railroad engineers and mechanics soon began to demand the original ones – the “real McCoys,” if you will, which you will indeed, because that’s where the expression comes from.
Railroad workers were demanding the real McCoy so often that the phrase got picked up into the greater cultural lexicon, where it came to mean anything genuine and of real quality. That’s a pretty impressive cultural impact for a railroad engine oiler.
Here, don’t take it from me – here’s someone from the Oil Museum of Canada explaining it as well:
I know you’re already likely flooded with Oil Museum of Canada content in your various social media feeds, but I hope you’ll just accept one more. There are some actual examples of oil-drip cups there and, yes, they’re the real McCoy.
Now, I know what you’re thinking: if this guy was such a big deal, why hasn’t he been in an ad for booze? Oh, you sweet simpletons, he has! Look:

Yes, Old Taylor, what seems to be usually described as a “budget-friendly” bourbon, once featured McCoy in an ad! For most people, that would be how you knew you actually made it, but I think for McCoy, revolutionizing a nation’s transportation industry and inspiring one of the most enduring idioms probably eclipses the booze ad.
Top graphic images:









These types of oilers are still in common industrial use.
James Rogers, author/compiler of The Dictionary of Cliches I keep at my desk–because this type of discussion arises all the time–suggests that the Real McCoy was either a oft-imitated boxer (“Kid McCoy”), a Glasgow Scotch (“A&M MacKay”), or heroin from Macao. But this post is better-documented than that little blurb, so it wins!
You’re darn tootin’ I have!
Edit: And he invented graphite lube – in 1916. 😮 Sciencespeed, sir!
This will always be the Real McCoy to me:
https://www.youtube.com/watch?v=Pav2f4b-1ZE
I thought it was in reference to a liquor smuggler during Prohibition named McCoy who would anchor just inside international waters for runners to pick up his wares. Since he didn’t water it down or cut it with dangerous methyl alcohol or the like as others did, people wanted the “real McCoy”. This invention predates that period, so I’m apt to think this is more likely the true origin.
My son did a report about Elijah McCoy years ago, and I am constantly telling people about him. Interesting note, we had read that Bones McCoy on Star Trek was named after him. Elijah was somehow related to somebody associated with the show. We were never able to verify this, so it might be B.S.
I believe I’ve driven by signs for that Oil Museum of Canada many times! It’s a funny area, because on top of that, there’s towns around by the name of Oil City, Oil Springs, and Petrolia, so they’re obviously big on fuel around there. Plus there’s a gas station around there we stop at, so they sell it too! South of Wyoming, Ontario, which I always thought was a surprising name for a town!
Huh, almost sounds like western PA. We have an Oil City and Petrolia as well.
Fascinating. Also fascinating is how the name helped. It sounds cool. “The real Smith” doesn’t sound as good and probably wouldn’t have stuck around. If your name isn’t right you may as well give up because you ain’t getting the booze commercials.
I’d always assumed it had something to do with the McCoys of the famous “Hatfield/McCoy” feud. And now that I know that Elijah McCoy’s family was from Kentucky, I’m left wondering if his father was related to (more likely “owned by”, although it pains me to even write that) the famous feuding McCoy family.
I’m pretty sure this post violates every anti-DEI rule currently put in force by Cheeto Jesus. So, good job and hats off to Mr. McCoy! Also, beware of Greeks bearing gifts.
Also, being a Canadian citizen (or, rather, a British subject born in Canada, since Canadian citizenship wasn’t fully a thing until 1947) doesn’t help, given current trade war and territorial expansion rhetoric
As an engineer who has worked for a company that specializes in automatic lubrication systems, I find this very interesting. Thanks for this tidbit!
This is why I love Autopian. Wonderful little nugget of information. Thanks for the education.
Next up, want to give us the low down on “balls out”? Or are such things not discussed at the less seedy taillight establishments you frequent?
I’m guessing “balls out” could have an origin in an old, simple mechanical system as well, the mechanical speed governor- https://en.wikipedia.org/wiki/Governor_%28device%29. Running “balls out” would be with the governor at the max, with the balls out wide, before it cuts speed/power/whatever.
This is my understanding of “balls out” as well, as told by the old timers tending the steam traction engines at the vintage farm equipment festival near me. Most of those steam engines use a centrifugal governor like that, and they’ll spin into a disk-type blur at full speed.
In a related theme, “balls to the wall” came from the throttle levers on early airplanes, which typically had spherical knobs on the end of them (similar to a lot of boat engine throttles). Full throttle meant pushing the levers forward towards the firewall, so “balls to the wall” referred to pushing the engine power to maximum, and now generally refers to applying maximum effort in any situation.
Neither of those sayings have anything to do with the dirty connotations most people assume.
Who Knows, knows! The most photogenic governor!
Bingo! A mechanical steam engine governor.