Yes this is my understanding of whats going to happen. I havent read the spoiler thread on the final book but you kind of pick things up here and there. I'm very much in support of the survival of a rump CSA .Certainly de-militarized and perhaps truncated by the creation of a black nation. To make the series a true ATL Turtledove shouldn't put things back together they way they were pre- 1861.
Why not reunify North and South? Having been separated for most of a century, they're not going to be the same sections that we had OTL. Obviously the second marriage is going to be a major headache for everyone involved. Unlike OTL, the Union military machine is a harsh, brutal thing, and the Confederates' hatred of the USA unquenchable. Even reunified, there is definitely going to be vast changes in the course of events to make it a "true ATL," which is not the point of the series in the first place. The point of the series in the first place is "It Can Happen Here." HT wanted to make his own version of that story and cloak it in an AH setting. Hence all the characters being North American (except for Schlieffen, but even then he was an outsider observing Americans), but I digress.
On the Morgenthau Plan, I don't think Philadelphia is going to worry so much about Confederate industry. For one thing, the CSA doesn't have anything close to the industry capacity that Germany had; I doubt it came anywhere close to what was in the Rhineland alone. The Confederates were already having shortage problems six months into the war; after Pittsburgh they did not have enough to slow down the USA juggernaut into Georgia. The Confederacy, quite simply, is not Germany. The CSA can never sustain a long-term war, industrially and militarily. The best they can hope for is a short campaign or two before the USA outgears them. If the USA wanted to avoid a fifth war with the CSA, it can easily do so on the political front, backed up with plenty of US Army power.
After the Freedom Party's death camps and a long history of anti-black killings in the CSA, how many blacks would still be around to set up a Black Republic much larger than 1 state? Would blacks move down from the north? There doesn't appear to be a lot of them up there. Any Black state would likely be in southern Alabama and Mississippi. The whites in the US would not want too large a state and they would demand it be as faraway as possible.
Two things. One, if the CSA was going to retain independence after 1944, it would be in both the USA and the Confederate blacks' best interests to give the latter group full citizenship privileges in the South. Let them balance out the whites in areas, or even outnumber them, thus indefinitely ensuring an anti-diehard turnout in local, state, and national elections (provided that enough blacks survive the population reductions to matter).
Two, if the CSA is going to be readmitted to the USA, again it would be in both the USA and the blacks' best interests to remain part of whatever political unit they're in, and not weaken themselves by creating their own state. The blacks can help the army of occupation by serving as auxiliaries, etc.
African-Americans living north of the Ohio River? They know better than to come down south and hope for a decent life, even if its under the protection of Yankee guns.
