Dear Rebprof,
As always a thoughtful post.
To be sure, history is "messy" and inconsistent and complicated, since it is may up of people, who are messy and inconsistent and complicated, and change over time.
A civic religion was created in the decades following the War, a common set of attitudes that allowed the sections to reunite. The elements of the Southern myth, or "lost cause" include that the war was over some other object than slavery. The Northern myth includes the creation of a Christ like Lincoln among others. The main losers in this common mythology were African Americans, forced into Jim Crowism in the South, and more genteel de facto segregation in most places in the North.
Was the Civil War a "good war?" No war is good, but can have good results. The good result of the CW is the end of American slavery and the permanent weakening of the racist beliefs that rationalized it.
There isn't a real controversy about the role that blacks played in the Union or Confederate armies. Blacks in the Confederate army had the roles that had in the South: slaves, laborers, servants etc. Blacks in the Union forces, started at this point, but progressed to something different, and greater.
What was the Confederacy, or rather why was the Confederacy? If its armed forces included, as the SCV stated in their "fact sheet" 80000 blacks, by implication, soldiers, its a different place than if those 80000 were slaves, servants, teamsters etc.
Because people are messy, inconsistent, complicated and all that, then there are cases, which nobody has denied, of armed blacks in the
CS forces. While a worthy subject for study, to claim that they were the equivalent of the 180,000 black troops fighting to end slavery is to misunderstand the actual situation.
Given the ugly instances of discrimination and racism displayed by the North and Union forces during the war years, a self-congratulationary tone is out of place. But the country was in a different, and with the benefit of hindsight, a better place after the war than before.