I think what the separatists like Rockwell wanted was to balkanize the united states, rather than ship the blacks to Africa, allow the blacks to have a country on American soil, carved out of a part of the USA.

Rockwell and the American National Socialist party campaigned against segregation and integration for separation.

The difference? a full split along racial lines, no longer co-habituating in the same country, each race has their own government and political representation within it, whites don't have to take care of blacks or be prey for black criminality, and blacks get to actually have their own political power that is undiluted by whites, and they no longer have to fear whites oppressing them or discriminating against them, by removing the potential threat posed by the other race, there would be no racial conflicts of tensions.

The whole intent of jews is to enflame racial tensions, this is why they reject the idea of race realism, because it removes the need for a conspiracy theory of white supremacy to explain racial differences in incarceration and achievement.

The main tool the jews used against the united states was always the preservation of the union as a whole, secession, which was guaranteed by the founding fathers, was the antidote for a lot of the nations problems, to keep them from coming about in the first place, everything from "the" American civil war to the failure to make good on the conditions for emancipation in that blacks would all be sent out of the the country to Liberia, would all have prevented the fate that befell the country from coming about, thus the jews used the clever manipulation of "but goyim, we need to keep the union whole, we can't let it all fall apart", Lincoln is known as the great emancipator, but he should have been known as the great incarcerator, keeping the south imprisoned within the united states, when it was their explicitly given right to leave.

Malcolm X has a great speech about this that is like 5 minutes long and worth listening too.