Well, tell that to my friend who just got through compiling a whole reference book on Black soldiers in both armies of the war. Tell that to the many descendents of Black confederates, who still have photos of their ancestors in Confederate uniforms.
Your prtisanship, plus no doubt your indoctrination in a collectivist, governmental indoctrination camp, has blinded your view of history. Washington warned us about that "spirit of party."
For the record, I am, politically above all else, ANTI-Democrat.
PS: The Radical Republicans are praised and adulated in every governmental textbook *I* have seen. They were called 'radicals" because that's what they were, and their aims are being steadily achieved, mostly these days by the modern Democratic Party.