The scoffing, I think, had more to do with the notion that Blacks who found themselves working for the Confederacy signed on freely out of a pro-confederate spirit. Now if the conversation has shifted to drivers, diggers, haulers, cooks, personal servants, rather than to volunteers at arms and official Black units you'll naturally see the response adapt to new claims. 0
Those who want to place slavery at the center of the controversy ignore the fact that slavery was far more secure in the Union than outside. Why? Because of the Fugitive Slave Laws that seccession rendered ineffective for retrieving escaped slaves.
Some clever people came up with that interpretation over the last 20 or 30 years. I'm not saying that nobody in 1860 might have thought that way. There were clever people then too. But that notion was very far from what most people, gripped by the passions of the day, would have said or thought. It's like one of those political paradoxes today that charm ironists but don't influence partisans in the least.
Some clever people came up with that interpretation over the last 20 or 30 years.”
I think that it’s more a matter of this fact having conveniently being left out in most 20th Century treatments of the War. That is the only reason it seems new. The people in the Antebellum US, both North and South, were keenly aware of this, which is why the Fugitive Slave Laws were such an issue.
“The scoffing, I think, had more to do with the notion that Blacks who found themselves working for the Confederacy signed on freely out of a pro-confederate spirit.”
Look for yourself, but I think that you will find the standard response was that it was entirely a fabrication. I would also add that the blacks who fought had reasons for having loyalty to the South. For one thing, the free blacks (some of who owned slaves, by the way) knew how freedmen were treated in the North and that the overwhelming majority of Northerners wanted nothing to do with blacks, even to the point of passing laws to keep blacks out of their states.
We need to rid ourselves of the Uncle Tom’s Cabin caricature of race, race relations, and slavery in the Antebellum period. It was a far more complicated and interesting set of relationships and attitudes than the race hustlers have led people to believe. Given your interest in the period, you might enjoy reading the Slave Narratives.