Violently Midwestern

The addition of Tim Walz to the Democratic Presidential ticket, and the Minnesota Governor's sunsequent bump to the national stage, and the way he leans into his Midwestern persona, has many remarking about the various quirks of people who live in this part of the country. Hot dishes, Minnesota niceness, etc. In a lot of ways, the very defintion of what constitutes the Midwest has been exapansive and fluid. This map has people reasoning those in the Rocky Mountains might consider themselves Midwesterners. For his part, White seems to indicate, at least in the Mid-19th Century, the region counted among it Western Pennsylvania and even New York. When we talk about the Midwest, and are serious about it, the absolutely proper roster is Ohio, Indiana, Michigan, Illiniois, Iowa, Missouri, Wisconisn, Minnesota, Nebraska, Kansas, and the two Dakotas. The overall image of the Midwesterner is a somewhat placid, politically moderate wheat and meat disitillation of America. It's sometimes dimissed as bland, and almost having an anti-culture--whatever one might say disparagingly about Boston or New Jersey or the South, it's at least distinct. What defines a Medieval American Midwesterner is evidentally something very different.
On the history of Iowa page, it's explained that the culture of the Midwest was eradicated by the Hersdmen of the Great Plains, but slowly seeped back in. This infers to very promeninet points; 1) That there is a very distinct culture of the Midwest, to the extent burning down their cities and killing off their men can be considered "genocidal" and 2) The Plains tribes, is largely not that, even if they would likely live in places we would today consider the Midwest. What it is, we don't know, or if White would have ever elaborate what "culture of the Midwest" meant. It's very likely trying to worldbuild this society was perhaps a major source of writer's block. However, I have a few ideas. As Kansas is no longer part of this "zone", the idea of corn field and slightly dusty stretches of land will probably be dropped. In fact, the Great Lakes now make up a larger part of the real estate, as as such water a larger part of their headspace--in war, in mythology, in how they eat. In the modern era, the image of the Midwest is largely "rural" compared to the coast, and of course, that would be technically the case here, but as most people are farmers, it wouldn't be that much difference between it and say, California.
But most prominently of all, the Midwest, Ohio in particular, can be said to be the epicenter of Feudalism. The 20th Midwest is sort of characterized by its gentleness, but the Medival Midwest may in fact be the most war-torn place on the continent. It's probably where the arms race is at its fastest, where armor and weapons development are the most iconic. It would be very interesting if they developed a unique form of a chivarly--a code (which, if the Middle Ages of yore are an example, probably not followed that much) of valor that was put throught the filter of "Minnesota Nice".