"It caused a lot of illness, including perforated stomach linings because, as we all know
today, maize is not broken down by the human gut without considerable pre-processing.
And even where it didn't cause sickness it still didn't provide much nitrition because it
wasn't digested properly"

The aborigines in Massachusetts had no trouble with corn. I have seen the stones they ground maize on, with dinnerplate sized depressions in a stone of suitable flatness and hardness. I do not know how they cooked it, since they apparently did not have pottery. My guess would be that they made little cakes of moistened ground meal on a small flat stone placed near the fire. I have never heard of digestive problems such as CK mentions. The Indians also grew beans, which together with maize have a desirable balance of proteins and vitamins. I would guess they also had to crush the beans.