In my world, an apocalypse happened, a nuclear war.

Fast forward to the future. In places like Vegas, New Fresno, and Lost Angels (post-apoc LA) I was thinking about agriculture, and after doing a little bit of research, I decided what their staple crops would be.

I planned on these settlements growing corn, beans, squash (and in some regions cabbage) as their main source of nourishment.

Here’s my question: Would this work? Could large, post-apocalyptic city-states base their civilizations on maize, beans, and squash?

**Criteria**

* Each of these cities has a population of several thousand people.
* I don’t know which livestock would work best yet.
* They have a reduced level of technology, say late 1800s, but with less manufacturing ability.