It became a thing in different places at different times. I'm curious to learn more about the history actually, because all the sources I can find are specifica

It became a thing in different places at different times. I'm curious to learn more about the history actually, because all the sources I can find are specifically oriented around political action and do not present any factual history. From what I could find about California, jaywalking is not illegal on most streets, but happens to be illegal when crossing most streets in densely populated areas. Specifically, you are not allowed to cross streets that have crosswalks at both ends unless you do it at the crosswalk. The current laws are from 1959 and seem to have been passed specifically to reduce pedestrian fatalities. These laws seems pretty successful at accomplishing that goal, and recent attempts to remove jaywalking laws over racial equality concerns have been blocked in the interest of public safety (rightly, in my opinion). To answer you question, in CA at least, it appears that pedestrians were kicked off after everyone had cars. Streets are unsafe for pedestrians, but it's because people drive on them, not the other way around.