Back in the 1910s, 1920s, the streets in American cities were a gigantic big old mess. You had pedestrians, horses and carriages, vendors, and street carts. It was a melting pot of everybody, which wasn't great news for people trying to encourage the sale of cars. If you have a great big hunk of lethal metal careering down a street, you don't want anything in its path.

The American automobile industry had a clever idea to clear their path. At the time, there was a derogatory word, "jay," meaning somebody who was unsophisticated or naive, especially someone from the country. The automobile industry took that word and invented the term "jaywalker" to imply that anybody stepping into the street was stupid, an idiot, or an unsophisticated person who didn't understand how cities work.

They created adverts to embed the idea that the pedestrian was the fool if they were the one crossing the road. They got schools and boy scouts involved, and used adverts everywhere to persuade people that the blame for accidents lay on the pedestrian, not the car. They essentially shamed people into leaving the streets to vehicles only.

As time went on, the narrative shifted from rural "idioticness" to illegality. Many American states began criminalizing the act of being a pedestrian in the street outside of a crosswalk. The cultural shift was complete, all because a manufactured word convinced everybody that walking was a crime.

By the way, in case any Americans don't know, jaywalking is not illegal in Europe.