This phrase, meaning that someone is good at one thing, but is pretty much useless at nearly everything else, is the epitome of back-handed-compliments. The origin actually comes from circuses back in the late 1800s and early 1900s. Now, these weren’t the type of circuses you think of now, trapeze acts and acrobats, elephants, lions and tigers. These were the shoddy circus days.
You see, even if these showmen could get lions and elephants, they didn’t have the means to haul them around in the post-civil war United States. I mean, cross-continental railroads were still being built! People had a hard enough time getting wagons over the passes, let alone exotic animals and tents and performers. And, this is where the phrase ‘Dog and Pony Show’ comes from. Their acts basically had to do with just that, dogs and ponies! Those animals were who did tricks, because that’s what the circus had.
So, they’d send someone ahead to arrange things and put up posters, these were small towns that didn’t have the facilities to house a large circus troupe, and then the ‘Dog and Pony’ circus would come to town.
Now, as far as I can tell, the first actual recorded account of the phrase, ‘One Trick Pony,’ comes from right here in Oregon, Salem if I have my facts in order. This guy, Charles B. Moors, born in 1852, recounts from being a kid, cannons being fired when Oregon gained its statehood and the capital building burning down. But he writes about a ‘One Trick Pony’ at the Pioneer Oregon Circus, held by the Cuffing Cousins, a horrible performance, with one tent, one clown, and a pony that only knew one trick. That trick was playing dead.
So imagine the folks of Salem, all riled up about the big changes their statehood was going to bring, hearing about the circus, getting excited and showing up at this shitty little tent where, inside, is a clown and a pony, and when the clown cocks his thumb back and pretends to shoot the pony, it falls over and plays dead, and “That’s the circus folks!”
People in the audience were pissed and went into an uproar, demanding their money back and shouting. I don’t know what happened after that, but I’m pretty sure shit went sideways. Also, I’m super stoked we have an idiom created right here in Oregon!