I don't split American history into different categories. It's all the same history. I actually don't think I said a thing about the civil war in this discussion. You mentioned the phenomena of "historical malpractice", and the example I provided is the most egregious form of it of which I am aware.
Do you know of a more significant example of "historical malpractice" than that of people trying to make the Declaration of Independence about slavery?
I think that is the worst of the worst, but I welcome anyone suggesting another example of historical malpractice which is worse in the degree of lying or worse in the level of significance caused by the lying.
To take a shot at that goal, I would suggest the lauding of John F. Kennedy as a hero for resolving the Cuban Missile Crises is a very serious example of historical malpractice. Nobody more deserves the blame for making a botch of the situation than John F. Kennedy, but all the historians treat him like the hero instead of the idiot that caused it.
Eras is probably a better word but regardless, American history does have readily identifiable ebbs and flows that allow for compartmentalization in discussions.
"I actually don't think I said a thing about the civil war in this discussion."
You didn't use that specific phrase; however, you did say in post 9: "Subsequent generations have reinterpreted it to be a condemnation of slavery" Your posting history in general and yours/my past discussions in particular have trended into CW talk even in non-CW topics. It is the most obvious and likely subsequent generation coming from you. - likewise, a comment like that would be most likely coming from me to be in the context of the early 20th century progressive era.
"Do you know of a more significant example of "historical malpractice" than that of people trying to make the Declaration of Independence about slavery?"
The way the question sits regarding the Declaration is unanswerable. Need clarity. Do you mean:
Do you know of a more significant example of "historical malpractice" than that of people trying to make the Declaration of Independence wholly and solely about slavery?
or:
Do you know of a more significant example of "historical malpractice" than that of people trying to make the Declaration of Independence in part about slavery?
The omitted items make a world of difference. Which question did you want me to answer?
"I welcome anyone suggesting another example of historical malpractice"
I think the entire body of work in regard to the Progressive Era takes the cake. The whole thing is a massive and flagrant coverup. Hence my username, and hence my main-target open source audiobooks.