Taking advantage of the lax rules to ask a very broad question, maybe too broad. Feel free to answer with your area of expertise, whether geographically or temporally.

Basically before the European conquest various states, groups, cities, federations, whatever existed in North America.

Unlike Aztecs and Maya which are very present in the popular culture, very little is talked about their northern neighbors. I would like to get a better view of what the political system on the continent looked like at the time.

The date is rough - anything goes that we have the data on.