I've always been kind of baffled as to why trains were ever added to dresses. Was it a short bride who decided to carry off her ill-fitting dress with panache that started it?
However they entered popular consciousness is irrelevant now, because we have seen their zenith in this beautiful Starship Enterprise dress.
Also, I can't help but notice the Ash Ketchum cosplayer in the background. You can see the gears turning in his head: "is that a Pokemon? By this point the answer is statistically likely to be yes. I mean, we have trashbags and swords for Pokemon, so why not?"