In article ,
Jie-san Laushi wrote:
Some of the Indians had maize
(US: corn), but I don't know how far North this extended

In the eastern woodlands and prairies, it extended at least to southern New
England and the Ohio Valley. In the western desert, not much beyond Arizona
and New Mexico. It was unknown on the West Coast.

Maize was grown as far north as the Gaspe Peninsula, where the native
people developed Gaspe Flint, an amazing cultivar that goes seed to
seed in ten weeks. It's used as an experimental subject in maize
research because it not only has a short generation time, but it has
a short stature and can be grown indoors. It's an impressive
accomplishment of indigenous agriculture to adapt a plant native to
hot dry climates to a cold short season maritime one.

The Mandan people of what is now North Dakota also raised maize. Before
the introduction of the horse made a nomadic buffalo hunting lifestyle
feasible, a lot of people practiced maize/bean/squash agriculture in
the river valleys of the prairies. Once the 'classic' Plains Indian
culture took off in the late 18th century, however, most of these people
got tired of having their harvests constantly stolen by mounted raiders,
and deserted their sedentary lifestyle for the new horse nomad mode.
These former agriculturists grew only tobacco once they became nomads.

I find that once acorns have been leached, they have a nut-like texture
(predictably, since they are nuts); I wonder if one could make acorn butter
(like peanut butter or hazelnut butter)?

I don't think they are high enough in fat to make a nut butter, but you
might try adapting recipes for chestnuts, another starchy nut. The French
use chestnuts a lot, including in the form of flour.