Three Sisters.

Corn or maize, beans, and squash were the most important food resources for nearly all Indians residing in the present-day United States. Called the "three sisters" by the Iroquois because they naturally grew well together, corn, beans, and squash provided the nutritional base and chief source of subsistence for most Indians until the twentieth century. Cornstalks supplied the climbing surface for bean vines, while beans and squash restored nitrogen to the soil depleted by mineral-hungry corn. By 1000 A.D., Indians living in the Southwest, along the Missouri and Mississippi Rivers, and in eastern North America grew all three crops. Many varieties of corn were utilized by different Indian groups, depending on the particular climate in their area. Corn that needed comparatively little water flourished in the semiarid Southwest, whereas quick-growing corn varieties suited the short growing season of the Canadian...