As always, I want to thank the Horde for its guidance and input on my reading list. As a result of comments, I dropped Masters and Lords and picked up an old copy of C.V. Wedgewood's 30 Years War. It really is an exceptionally well-written book, rising to that McPherson level of historical synergy.
One point she makes early is understanding the differences in political identity of the time. Being French may not have meant as much as being, say, Catholic. Or being Catholic may not have meant as much as being the vassal of Sir suchandsuch.
Again this is still about the Civil War. I'm coming to think of the thing as the radical actualizing of Enlightenment principles through steel. But to really understand that, I've had to understand how much of our political reality would have been new at that time. Individual rights, fealty before The nation-state, free labor etc. are modern ideas. And at the time of The Late Unpleasantness, they were still, relatively, untested.
America was, in so many ways, an experiment.