Indigenous American agriculture was based on corn. Traces of cultivated corn have been identified in central Mexico dating back ten thousand years. Twelve to fourteen centuries later, corn production had spread throughout the temperate and tropical Americas from the southern tip of South America to the subarctic of North America, and from the Pacific to the Atlantic Ocean on both continents. The wild grain from which corn was cultivated has never been identified with certainty, but the Indigenous peoples for whom corn was and is their sustenance believe it was a sacred gift from their gods. Since there is no evidence of corn on any other continent prior to its post-Columbus dispersal, its development is a unique invention of the original American agriculturalists. Unlike most grains, corn cannot grow wild and cannot exist without attentive human care.

Roxanne Dunbar-Ortiz, An Indigenous Peoples' Hist…, loc. 44971