Very cool map.
One quick question: Some of the new states don't have state names, just capitols. Is there a reason for that? I specifically noticed it in the central states where Topeka, Colombia and Galesburg are the capitols, though other areas had this omission as well. (I live in Kansas and so naturally checked here immediately to see what you did to my home. No real qualms with your divisions, they make perfect sense, but I was just curious on the names.)
Also, though this would take more work, but it would be really cool to take this map and overlay it with a terrain map and then redraw some of the boundaries to match up more closely with mountain ranges and streams/rivers. Specifically I'm thinking out west where you still end up with a bunch of long straight lines.