Empire by Collaboration. Robert Michael Morrissey

to farm these soils until the invention of steel plows in the nineteenth century. Native Americans did not have plows or metal farming tools of any kind, and so they normally did not exploit the prairies as farmland. Instead, they used hoes to farm the fertile soils of the bottomlands. Meanwhile, although game species like deer and elk could be found in the tallgrass prairies, they were most commonly located at the “edges” where grasslands and forests overlapped. Remarkable evidence of prehistoric trash pits suggests that prairie environments were largely underutilized. In one Huber phase Oneota trash pit from the 1400s, for instance, only 2.4 percent of the animals used by the residents came from the prairie, while the vast majority came from the valley floors, forests, and wetlands.³³ This was probably typical. For much of the prehistoric period, it seems clear that the prairie itself probably went relatively unused by human inhabitants of the region.³⁴

      This is important because prairie made up close to 55 percent of the land in the modern state of Illinois, even more in the modern state of Iowa. Since they could not easily exploit this land for farming, and since their preferred game did not usually congregate in prairies but on its edges, this meant that the Native inhabitants of these regions left prairies as a largely untapped ecosystem. Here were calories, produced by grasses, which the Oneota villages had little means to exploit. Humans, of course, could not eat the grasses, nor could they easily replace them with edible plants.

      The large-scale invasion of the bison into midwestern grasslands from points west thus created a great new subsistence opportunity for people whose climate was changing, and particularly for farmers whose calorie yield was compromised by both rainfall shortages and possible flooding. Newly arriving bison of course could use the prairie grasses, eating them up to become what one historian calls “reservoirs of biomass.”³⁵ In ecological terms, bison were able to convert the “vast energy stored in the … grasses for human use.”³⁶ Deer and elk were certainly important before, but bison arrived in the region in huge herds and were relatively simple to hunt, provided one had a cooperative group to help direct the animals to a kill zone. Indeed, bison hunting produced calories on a totally different scale than deer hunting: each animal weighed 2,000 pounds, containing at least 675 pounds of useful meat. Hunts in the tallgrass prairies regularly yielded hundreds of animals at a time.³⁷ For Oneota people accustomed to starchy agricultural diets, the new resource created a dramatic increase in nutritional quality, fairly quickly.³⁸ The invasion of the bison brought tremendous change to Native life in Illinois between 1500 and 1800.

      By turning the prairies from wasteland to productive, the arrival of bison vastly increased the amount of calorie-producing land in the future Illinois Country. The new animal resource was so attractive that it inspired migration among many of the inhabitants of the region. The eastern spread of bison pulled more Oneota people to the West, back out onto the prairie peninsula and closer to the plains environment, as they increasingly specialized in bison hunting.³⁹ This “bison revolution” confirmed the Oneota’s status as a “bridging culture,” connected to the two biomes and lifeways of the woodlands and the plains.⁴⁰

      To be sure, not everyone went west. The so-called Huber phase Oneota sites remained in the northern part of the Illinois River Valley. These were prosperous places, now augmented and altered by bison exploitation. Trash pits at the Fisher site in the upper Illinois Valley from this period reflect a great deal of diversity in the diet of these Oneota people, who now added bison to an extensive list of flora and fauna that they exploited on a seasonal and cyclical basis.⁴¹ The survival and persistence of these Oneota culture groups in the wake of Cahokia set the stage for the protohistoric and historic transformations in Illinois.⁴²

      Meanwhile in the East, Algonquians living south of Lake Erie and in the Ohio Valley were also suffering from climate change that made agriculture difficult. As in the Illinois Valley, this produced violence and warfare, even what one archaeologist calls a period of “ethnic cleansing” as proto-Algonquian groups struggled to survive.⁴³ Some Algonquians, concentrated in settlements just to the south of Lake Erie, interacted and shared pottery traditions with a group identified by archaeologists as the Fort Ancient people, who lived in modern-day southwestern Ohio.⁴⁴ Pottery traditions and archaeological assemblages suggest that these proto-Anglonquian groups began to trade with Oneota peoples at the Huber phase sites in the upper Illinois Valley in the 1500s. Before long, they were in close contact with these Oneota groups, carrying prestige goods back and forth across the modern state of Indiana in a flourishing trade network.⁴⁵ Interestingly, calumet pipes, the diplomatic tool of western Siouan-speakers, were some of the materials that Algonquians received from this new trade.⁴⁶

      But it was not just prestige goods and diplomatic symbols that passed back and forth between these Algonquians and their Oneota neighbors. Sometime in the 1500s, the Fort Ancient culture adopted another facet of the lifeway of their neighbors to the northwest: they started hunting bison. Limited numbers of bison had arrived in the Ohio Valley in the 1500s. There is no way to know whether the Fort Ancient hunters learned bison hunting from their Oneota trading partners, but it seems possible. Like their neighbors to the northeast, these Ohio Valley hunters experienced a bison revolution.⁴⁷

      It was probably bison that inspired the next important turning point in this story. In the late 1500s, a new pottery tradition known to archaeologists as Danner-Keating shows up in the Huber Phase sites in the upper Illinois Valley. Importantly, this Danner-Keating tradition strongly resembles pottery found in the Fort Ancient sites. Moreover, a very similar pottery tradition, which may be a root tradition for Danner, is found in sites to the south of Lake Erie.⁴⁸ Examining this pottery, scholars now speculate that the people identified with the distinctive Danner-Keating material culture and its possible Fort Meigs antecedent moved over time across the established trade networks between the Lake Erie settlements, Fort Ancient sites, and Huber phase Oneota settlements, and into the northern Illinois Valley. By the early 1600s, Danner-Keating appears in the same locations long occupied by the Huber phase, whom archaeologists believe were the historic Winnebago. Before long these Danner-Keating migrants replaced their hosts.⁴⁹ It is almost certain that the bearers of this new Danner-Keating archaeological tradition were the historic Illinois and their Miami kinsmen.⁵⁰

      Was the invasion violent? It’s not clear.⁵¹ As we have seen, many Oneota peoples—Siouan-speakers and the ancestors of the Missouria, Ioway, and other groups—had recently moved west from the Illinois Valley to exploit the bison more intensively. The proto-Winnebago moved north out of the Illinois in the early 1600s. The southern Illinois Valley remained a vacant quarter in the wake of the Oneota-Mississippian violence between 1200 and 1400, and the new bison hunters saw the opportunity to seize it. The broad history is one of “replacement” or possibly “intermixture,” as the Illinois came to this region.⁵² But one thing is clear: the Illinois were colonizers.

      In his study of the Cheyenne in the Great Plains, historian Elliott West tells how the Cheyenne moved out of the upper Mississippi Valley onto the Plains to exploit the bison in the 1800s, reenvisioning the region and giving it “a new meaning.” Committing fully to an equestrian lifestyle, they became the “called out people.” Of course, the Illinois were never equestrians, but their migration west in the early 1600s may have had a similar dynamic. They were committing to a new lifestyle, a new ecological resource, while invading a rich region, much of which had long been left vacant by climate change and violence. Like the Cheyenne’s migration, this was a bold, opportunistic process as they reenvisioned the tall grass and its possibilities.⁵³

      Over the course of the next generations, the Illinois-speakers colonized the whole region formerly occupied by the Oneota in modern-day Illinois. Moving into their new homeland, the Illinois adopted bison hunting as the basis of a radically new lifeway. Perhaps because the Illinois still spoke an Algonquian language at contact, French eyewitnesses often did not emphasize in their accounts how different the Illinois were from other Great Lakes Algonquians by that time. In fact, upon moving into the prairies, the Illinois embarked