Stuff like chili often already exists somewhere before it gets popularized. The depression certainly didn't invent American style spiced beef stew. But much like cowboy breakfast (beans, salted pork, coffee) it was simple, cheap, and could stretch protein to feed a whole family.

Wikipedia gives a decently quick tour of chili's evolution.

I've been spouting about the "chili queens" of old San Antonio as the origin, but it sounds like they were more significant as an early analog to food trucks that drove chili across cultural gaps. The origin of that food sounds like it originated back, at least, to indigenous peoples and does sound like a staple of cowboys/vaqueros long before the Great Depression.

Then there's Cincinnati-style chili, "developed by Macedonian and Greek immigrants, deriving from their own culinary traditions", so that merging of another style under the same name might muddy the water when it comes to talking about the origin of spiced meat bits.

Yup, I can vouch for that. Actually it's about time I made some again...