1. I don’t know whose site you linked, but I don’t see anything that says that thee were even brigade level black units. Instead, what he describes is the involvement of a few here and a few there. For example:
“In Lynchburg 70 men enlisted to fight for the defense of Virginia soon after it seceded.
In late April, 60 black Virginians carrying a Confederate flag asked to be enlisted.
In Hampton 300 blacks volunteered to serve in artillery batteries.”
Of course, over all when the entire Confederacy is taken into a account, small groups like these could aggregate into a fair number, which is what the author you linked claims. Nevertheless, he doesn’t claim that there was a freedman’s brigade or division, for example.
As for “integrated units”, I would wager that almost all units were integrated in the sense that blacks were present performing various tasks. The issue is whether not whether they were there, but whether they did any fighting. Gates is conceding that many fought. If you include individuals of mixed race, the number could be several tens of thousands, which isn’t much considering the size of the armies, but it would be interesting nonetheless.
2. I agree with you regarding my comment regarding “people like Gates”. I should have simply said the typical liberal. You can find many of them calling him a heretic for saying the many blacks actually fought for the Confederacy. In any event, I should have left Gates out of it.
3. “A long-standing structural or institutional factor can’t be the cause of a specific war at a specific time.”
If we accepted this, then slavery couldn’t have been a cause either because it was both a long term institution and a structural factor in the economy of the US, not just the South. Disputes over these sorts of things do lead to conflict. And, of course, every conflict occurs at a specific place(s) and time(s). For example, while I agree that “borders” by themselves don’t cause wars, disputes about borders certainly do.
3. “Most people recognize that all good wasn’t on one side and all evil wasn’t on the other.”
Now it’s my turn to echo you. The Manichean view of the War is not uncommon, and “You don’t have to look very far to find people who do make those claims. Some of them are right here on Free Republic. There are others elsewhere on the Internet.” ;-)
It wasn't so much the existence of slavery as the possible expansion or collapse of slavery, the growing abolitionist and proslavery movements.
If slavery had been a universally accepted institution, this particular war probably wouldn't have happened.
But it's hard to see how this particular war, at this time, with these sides would have happened without slavery and the conflicts surrounding it.
Of course there were conflicts about the Constitution at the same time, but since most conflicts in constitutional interpretation are resolved peacefully, one has to ask what made the conflict in 1860 so different.
Well, that's the thing about the imaginary units. Nobody really says how large they are. I suspect most people assume they were brigades or regiments, since those units figure most prominently in the battle histories. Of course Black Confederate brigades and regiments aren't mentioned in those histories, and it's hard to believe that there could have been battlefield groups of a thousand armed and uniformed African-American Confederate troops that nobody noticed. Maybe those who say that the CSA had Black units mean battalions or companies or platoons or artillery batteries, but the ambiguity is what keeps the Black Confederate story or myth alive.
I think you will find that Southerners of the period knew that slavery couldn’t expand within the US because outside of the South the conditions for plantation agriculture didn’t exist. So, even if slavery were permitted in a new state, they knew that the slave economy and culture wouldn’t take hold.
Look at the articles in magazines like DeBow's Review. There was much support for expansion beyond the boundaries of the US, for annexation of Cuba or parts of Mexico or Central America. Plantation economy and culture probably couldn't survive out on the Great Plains or in the Rockies, but many slaveowners were committed to expansion. If the legislation was in place, uses would have been found for slaves in agriculture, ranching, and mining.
The abolition movement was viewed as extremist even in the North, and I don’t believe it was growing at all prior to the war. I also don’t think that there was a growing proslavery movement. I would agree that those involved in the controversy over slavery became more intransigent in their views after 1830 or so.
I don't think it's so much that the movements on the extremes were growing, but that the center was fracturing into a Northern and a Southern consensus that had little in common with each other.
The Corwin Amendment addressed the slavery issue squarely and would have resolved the issue in the strongest possible way to protect slavery forever. Lincoln and the North (except for abolitionists, who were few) supported it. I glad that the South rejected it.
George III and Lord North could have offered the colonists in 1776 everything that they'd wanted in 1774 or 1775 and more and it wouldn't have convinced the Continental Congress to accept their rule. Things had gone too far. It was too little too late.
So it was with the Corwin Amendment. The secessionists were already on their way out the door and any concessions the government offered wouldn't be accepted.
Also, the Corwin Amendment didn't address the question of slavery in the territories which had been so important. It implied that the North had won that battle . For Southerners to accept the amendment would have meant settling for less. To be sure, seceding states would have lost their claim to the territories -- or had to fight for them -- but independence would have been compensation for that loss.
What's more, if Southerners believed everything they said about Lincoln and the Republicans, it's clear that they wouldn't have been able to trust the federal government to honor the amendment. The idea of an unamendable amendment was pretty dodgy and might not have stood up in the courts anyway.