Every Thanksgiving I think about the foods that Native Americans shared with those starving white strangers who had arrived from across the big water. We don't know the truth of that apocryphal story, but we do know for sure that the Native Americans in that corner of North America cultivated three important crops. Corn, beans and squash insured their survival through the harsh winters, and this triumvirate was called "The Three Sisters." Not one of these plants was native to the region but all were from the Americas.
Maize, which means "that which sustains us" in Arawak, is the proper term for corn. "Corn" is old English word that original referred to any grain. But colonists called the Native American plant "Indian corn" to distinguish it from the Old World corn. Maize was probably the earliest domesticated plant in the New World. Over 8,000 years ago the ancestor of maize grew wild in central Mexico. Its cultivation allowed the sophisticated civilizations of Mesoamerica to arise, and maize slowly but surely made its way north and east; arriving in what became New England around 900 AD.
But the oldest plant cultivated in the region was squash. Over 2,000 years ago Native Americans were growing two kinds of squash. The word is Algonquin meaning "eaten raw." These plants migrated north as well from Central America and were apparently easier to cultivate than maize.
Beans originated in the Andes and they include the common beans, runner beans, lima beans and butter beans. This was the last crop grown by our friendly Indians. By 1300 the three sisters were thriving together. The corn provides structural support for the beans to trellis on. The beans fix atmospheric nitrogen into the soil, which helps the corn survive, and the squash leaves cover the ground and suppress weeds.
The pilgrims were given these crops, taught the proper way to plant them and the rest, as they say, is history.