Earlier quoted context omitted.
> the original fast food was hot dogs and that's almost entirely gone now. Curious about this history. According to Wikipedia, fast food was common during antiquity, while the hotdog wasn't invented until the 1400s. White Castle seems to be recognized as the origin of modern day fast food and it opened as a hamburger joint.
In antiquity it was more what we might call street food or fast casual. What really defines fast food is mass production and uniformity.
Interestingly, I always assumed that “fast food” meant the type of food; so a hamburger, even if not made from mass produced ingredients, would always be a “fast food”.