Yeah, that area made sense to me. I would point out that both Missouri and Kansas are based on tribal names, so, you could stick with those for those regions. Perhaps not coincidentally, the two areas of those states that you have not named roughly coincide with where those tribes lived. So the Topeka state could still be called Kansas (or Kansa) and the Colombia area could still be called Missouri.

Also, the area around Chicago and Green Bay was settled by the Potawatomi, so that could be a name instead of West Michigan. The Galesburg state could possibly be called Illinois since it is named after the native tribe the Illini, though, I'm not sure if their natural territory actually overlaps with what you have here.