The North American tribes got their corn (among other goods) from the Mesoamerican civilizations

Exotic items clearly imported from Central America have been repeatedly uncovered in the archaeological records within the traditional territory of the northerners collectively known aptly as the ‘Pueblo’, or town peoples.

Such items include, but are not necessarily limited to, copper bells and macaw-parrots (the Hopi people of U.S. northern Arizona do indeed have a parrot clan — pic 3); utensils such as corn-grinding mano-metates; architectural features such as platform mounds, ball-courts (pic 4) and residences; and particularly their cultivated plants that originated in Mexico, especially the ‘Three Sisters’, maize-corn, beans and squashes.

This influence is also seen in pottery styles and artistic iconography, the latter exemplified by the mysterious and ubiquitous T-shape symbol (as found in Pueblo doorways and tablita headdress, plus Meso-American funerary masks).

Wow.