Spring planting is about ready to begin once again on the Illinois prairie, continuing a tradition that began thousands of years ago.
The first American pioneer farmers arrived here in the Fox River Valley area in the late 1820s. But the region’s Native People had already been farming for thousands of years by the time those first settlers arrived.
Most experts previously believed that agriculture in what is now the continental U.S. was imported from Mexico, along with the trinity of subtropical crops: maize (corn), beans, and squash. What is now accepted, after decades of archaeological work, is that the eastern United States is one of about ten regions in the world to become independent centers of agricultural origin.
The initial four plants known to have been domesticated by those earliest, pre-maize prehistoric farmers were goosefoot, sunflowers, marsh elder, and squash. Several other species of plants were subsequently added to the list of domesticated wild plants.
After 200 BCE when maize—corn—from Mexico was introduced into what is now the eastern United States, the Native People of the present-day United States and Canada soon stopped growing domesticated varieties of native plants, switching to an agricultural economy based on growing fields of maize complimented by beans and squash. As that evolution took place, the cultivation of domesticated native plants declined until it was almost wholly abandoned, and the domesticated native plants quickly reverted to their wild forms.
Horticulture intensified in the Woodland period, and most Native American populations began living in villages near their fields. In about AD 800, corn and beans reached the Mississippi Valley, and by about AD 1000, the Mississippian culture that relied on corn, beans, and squash was established in Alabama.
Squash of the Cucurbita pepo var. ozarkana variety is considered to be one of the first domesticated native plants in the Eastern Woodland region, having been found in use here some 7,000 years ago. However, it doesn’t appear to have been thoroughly domesticated until around 3,000 years ago.
That earliest variety of squash was originally raised for its edible seeds, and used for small containers (gourds) when dried. Squash with edible flesh came quite a bit later.
Other edible native plants domesticated by the region’s Native People included little barley, goosefoot or lamb’s quarters, erect knotweed, maygrass, sumpweed or marsh elder, and sunflowers.
These edible plants are often divided by those studying the subject into “oily” and “starchy” categories. Oily edible seeds are produced by sunflowers and sumpweeds, while erect knotweed (not to be confused with its invasive Japanese cousin) and goosefoot, a leafy vegetable, are starchy. Maygrass and little barley, both of which are grasses that produce grains that may be ground to make flour, are also starches.
So how have we discovered all this new information? According to the most recent findings by archaeologists, humans were already collecting native edible plants by 6,000. Then Native People discovered by could modify them by selective breeding and cultivation. Archaeologists confirmed that process in the 1970s when they began noticing significant differences in seeds, burned and otherwise, collected in Native Peoples’ village sites, especially when those seeds were compared to their counterparts still growing in the wild. When carefully studied, the seeds collected in village sites were not only larger, but they were also easier to separate from their shells, husks, or chaff. It was those comparisons that led archaeologists to conclude ancient farmers had begun manipulating the genetics of wild plants by selective breeding much longer ago than previously thought.
One of the major regions where these successful efforts at ancient agriculture flourished is right here in the middle Mississippi River Valley, stretching from Memphis in the south to St. Louis in the north in a belt roughly 300 miles on either side of the river in the current states of Illinois, Missouri, Kentucky, and Tennessee.
So far, the oldest-known archaeological site in the United States where ancient people have been found to be purposefully growing—rather than gathering—food is the Phillips Spring site in Missouri. At Phillips Spring, dating from 3,000 BCE, Archaeologists have found large numbers of walnuts, hickory nuts, acorns, grapes, elderberries, ragweed, bottle gourd, and the seeds of a gourd that produces edible seeds that is the ancestor of pumpkins and most squashes. The gourd seeds found at the site were significantly larger than the wild variety, leading archaeologists to determine the plants’ genetics had been purposefully manipulated by native farmers who selected, planted, and then carefully tended the seeds that produced ever larger and more nutritious seeds. And eventually, continual genetic manipulation led to the gourds producing edible flesh as well.
By 1800 BCE, Native People considered part of the Late Archaic cultural tradition in our region of the United States were cultivating a number of different plants. At the Riverton Site near downstate Palestine, IL in Crawford County, archaeologists have excavated one of best-known sites that illustrate the ancient people’s cultivation and domestication of native plants. At the Riverton Site, 10 dwelling houses have been excavated and studied, suggesting a village with a population of between 50 and 100 people. The fire hearths and storage pits excavated turned out to include a large number of plant remains. Among those remains were large numbers of seeds goosefoot, also called lamb’s quarters that the scientists determined came from cultivated and domesticated plants. They reached this conclusion because some of the seeds had husks only a third as thick as the plants’ wild varieties, making them much easier to process into food after harvesting.
As the years passed into the Middle Woodland cultural tradition, gardeners continued to cultivate and improve squash and gourds as Archaic Indians had done, but they also domesticated several other native plants that are considered to be weeds today. Building on their knowledge of Illinois’ native plants, Middle Woodland people began to establish gardens of goosefoot, marsh elder, little barley, maygrass, and other varieties of squash. Each autumn, they saved seeds from the best of the plants growing in their fields and then planted them when spring rolled around again. Eventually, these Native People became increasingly committed to particular plots of land and created a way of life organized around both wild and domesticated plants.
But change, in the form of maize, was just over the horizon. Strangely enough, though, as well as we know maize—we’ve been cultivating it around these parts for many hundreds of years now—we know very little about its origin. Many of those trying to figure out where it came from have fingered a grass named teosinte as the ancestor of modern corn. But there’s a fairly serious problem: Teosinte does not have a cob. This has led some of those looking into the mystery to suggest corn’s ancestor was some other wild grass that has now disappeared entirely.
Researchers Margaret Bunson and Stephen Bunson, suggest in the Encyclopedia of Ancient Mesoamerica that: “The wild maize plants altered by mutation were collected by early inhabitants of Mesoamerica and slowly domesticated. The wild form appears to have become extinct, possibly through backcrossing with domesticated forms.”
One problem is, however, that this “wild form” of corn has never been found in either the historical or archaeological record.
Another significant problems is there is no evidence that the early peoples of the Americas ever used or harvested teosinte. Finally, it has been theorized for a long time now that the Maya of Central and South America had cultivated and crossbred teosinte into maize. But no evidence has ever been discovered of this, either.
About all archaeologists and plant scientists have been able to nail down is that maize quickly became the most important staple grain in ancient Mexico. Ziz maize suddenly appeared about 4800 BCE on the Gulf Coast of Tabasco, Mexico, for instance. But there are no known wild specie of it in that area, suggesting it was imported, even at that early date, from somewhere else. After its abrupt appearance, the cultivation and genetic enhancement of maize became the focus of ancient American farmers.
But while maize quickly became the most important food grain for ancient peoples beans weren’t far behind. According to most current evidence, beans were originally domesticated in Mexico and Guatemala—the same areas where Zia maize was developed. The really neat thing about the beans those ancient farmers crossbred and improved so long ago is that beans’ proteins naturally complement the proteins in maize. Beans, it turns out, produce the acids lysine and tryptophan that nicely complement the amino acid zein from maize.
So with the invention of corn and beans, two of the legs of the Native Peoples’ Three Sisters—corn, beans, and squash—were in place where they joined the third leg that had already been undergoing genetic breeding for thousands of years.
It took a while, but gradually maize and its complimentary beans spread north into the Mississippi River Valley, where its cultivation quickly displaced growing the region’s domesticated crops. Corn, beans, and native squash and other gourds caused the abandonment of the old, locally developed, strains of little barley, lambsquarters, erect knotweed, maygrass, sumpweed or marsh elder, and sunflowers, and the reversion of the cultivated strains of those plants to their native states.
Now, many centuries after corn and beans made their way north of their native Mexico and Central America, they still make up the bulk of the fields farmers in the Fox Valley plant. Granted, today’s soybeans are a strain developed in Asia, where they were being grown as long ago as 7000 BCE. It has always seemed ironic to me that our modern soybeans were developed by the descendants of some of the same people who crossed the land bridge to North America tens of thousands of years ago to become the people who also invented corn. All of which is nice historic and prehistoric symmetry, don’t you think?