In much of Northern America, the transition from the hunting, gathering, and incipient plant use of the Archaic eventually developed into a fully agricultural way of life. In the lush valleys east of the Mississippi River, societies grew increasingly dependent upon plants such as amaranth, sumpweed, sunflower, and squash; their plentiful seeds and flesh provided a rich and ready source of food. Many of these plants were eventually domesticated: sumpweed by approximately 3500 bce and squash and sunflowers by about 3000 bce. By perhaps 500 bce the production of these local cultigens had become the economic foundation upon which the ...(100 of 3151 words)
