What allowed native americans in mexico to settle cities larger than those in areas to the north?

I think it was the quality of the land where soil was fertile enough for farming.  These helped feed a large population that helped the people settle in to these new areas where they can fend for themselves. As a result, the population grew and civilization flourished.

silk

indigo  

rice

all the other answers are wrong

an economic reason that the south needed a reconstruction plan is that plantations, factories, and other businesses were destroyed during the war.