The modern idea of carnivals began with the Chicago World’s Fair
It’s estimated that one out of every four Americans alive at the time attended that Chicago World’s Fair during the six months it was open. In modern terms, that’s the attendance of this year’s Super Bowl plus this year’s Wrestlemania, multiplied by 40. So, you know, a lot of people.
The World’s Fair was famous for the debuts of all sorts of technical marvels and even a performance by Nicola Tesla, who designed the AC lighting for the whole fair. However, let’s forget about all of that and focus on the far western side of the map, literally on the other side of the railroad tracks from the rest of the showcases. This was the Midway Plaisance carnival, which literally every carnival and fair in America ever since is in some way based on structurally. It had the rides, it had the sideshows, it had the food vendors, and even modern carnivals use the term “midway” to describe the arrangement of amusements influenced by this particular fair.
Honestly, the electronic gadgets in the fair were probably cooler, but it was the carnival configuration that lived on.