I've more or less been following this from the beginning and have been following comments by the Author outside the official story, it would be difficult to connect them all in once place, but I'll go through them from west to east... (I know he responded to a bunch of posts, but I still wanted to post it)
- Arizona Territory - The US is taking it. By far the least populated area of the Confederacy, easily accessible from the rest of the Union, etc. And even less objection because...
- Texas - In some of the Infoboxes, Texas is listed as an independent country and we've seen the author start the discontent from Texas toward Richmond, unclear whether keeps its state borders (which are OTL + OTL Oklahoma Panhandle)
- Indian Territory - The plan is apparently to keep it independent but completely politically/militarily dominated.
- Kentucky - We spent *weeks* discussing what happens to Kentucky post-war, I *think* at this point, the only things that the author has said (on the Col Sanders posting) that wouldn't require retconning is that a *large* number of years post-war, there will at least some part of Kentucky that will cheer his death. I'm curious to see where he lands.
- Tennessee - Too many people, too far into the Confederacy. If grabbing Kentucky was *difficult*, grabbing both would be a complete nightmare. And with both the OTL WWI lack of interest in reindustrializing Germany *and* the WWII level of destruction of Germany, the CSA is probably looking at 10-15 years of trying to bring its industrialization back to 1913 levels and another decade before catching up is possible.
- Key West, probably useful, middle of nowhere (almost as bad as Baja at this point). The US *might* even want part of the mainland, I don't know if the railroad goes all the way to Miami yet...
- Virginia. The Two Virginia counties on OTL Delmarva are almost as much of a given as Arizona Territory. Expect to see *very* large guns built by the US on the side facing Norfolk (and possibly in other directions), the question is not whether Northampton County, Virginia will become a US Naval Base, the question is how much of the current county will be *outside* the Naval Base*. The US will make as certain as it can (without taking the entire confederate coastline of the Chesapeake) that the Confederates can not keep them out of the Chesapeake again. (Could the D&C Canal be dug out to the point that it would take Capital ships???). Additionally, while the US probably will take everything inside the OTL US Beltway, it basically depends on whether Washington DC will ever be a living city again, or if it will basically become a Necropolis (and I'm not sure what the author has decided there.
As for the remainder of the USA/CSA border (which is mostly ozark and appalachian mountains), I could easily see current borders being kept.
For all of the comments on the Gallapagos, Wallops Island, Virginia is also part of what the US will grab, so that will probably be the launching facility at least at the beginning of the space race.