
It's a map of state boundaries if all locations were required to be closest to existing state capitals. Chicago is closer to Madison than to Springfield, so it becomes part of WI. Southern GA is closer to Tallahassee than to Atlanta, so it becomes part of FL. El Paso is closer to Santa Fe than to Austin, so it becomes part of NM. Philadelphia is closer to Trenton than to Harrisburg, so it becomes part of NJ. Indeed, New Jersey becomes one of the most populous (if not *the* most populous) states because it also includes New York City, which is closer to Trenton than it is to Albany (or even to Hartford). OTOH, NJ actually loses some of its southernmost areas to DE (because they are closer to Dover than to Trenton).
The map is primarily a "here's a way to redraw state borders" fantasy rather than a "here's some other way states could have developed" fantasy. And yet, some state boundaries actually *could* have followed the lines given here. For example, as I once noted in soc.history.what-if, "Originally, the Illinois Territory extended only to the southern edge of Lake Michigan. What is now Chicago was in the Wisconsin Territory, as was a large amount of northern Illinois. Suppose that in admitting Illinois as a state in 1818, Congress had *not* extended the boundaries of Illinois northward..."
https://groups.google.com/d/msg/soc.history.what-if/pdH1rwCm49E/SJTgvIazK4oJ Then Illinois would look very much like on this map--and would have a much more "southern" political orientation
Or take Utah. This map would not give Brigham Young all he wanted for "Deseret" but still it would have put far more of the Mormon community in the West under one state government than happened in OTL--in particular, the large Mormon communities of southeastern Idaho, eastern Nevada, and southwest Wyoming would be included in Utah. As for Michigan, the map pretty much undoes the consequences of the Toledo War.
https://en.wikipedia.org/wiki/Toledo_War
Any other possibilities suggested by the map? (I put this in the pre-1900 section because most state boundaries were determined by then.)