South and Central Americans built amasing cities and had a relatively developped agriculture and trade. They also developped writing, mathematics and calendars, which they needed for their architecture and crops.

Many great civilizations collapsed long before the Spaniards explored and conquered the place, and some of the cities were in some level of decay, inhabited by a different, less advanced group.

It seems plausible the "good times made weak men" caused the big cities to lack the skilled and smart people necessary to make the place run properly.

Up North? Ehhh, some modest seasonal camps with limited agriculture for some, pure hunter-gatherers for other very large territorire.

South and Central Americans built amasing cities and had a relatively developped agriculture and trade. They also developped writing, mathematics and calendars, which they needed for their architecture and crops.

Many great civilizations collapsed long before the Spaniards explored and conquered the place, and some of the cities were in some level of decay, inhabited by a different, less advanced group.

Up North? Ehhh, some modest seasonal camps with limited agriculture for some, pure hunter-gatherers for other very large territorire.