I was explaining this to my husband the other night, that human history is rarely as simple and clear-cut as we want to believe, or as history classes tell us. The American Civil War, like all civil wars, was really the culmination of a number of conflicts and disagreements over a period time between two disparate cultural groups who felt nothing in common connecting them. Slavery was the obvious and egregious of those conflicts, and became the rallying point.
Agree... Slavery was the reason people could get behind. Slavery was the thing which would get people to rally for a rebellion. Slavery was why they pushed away. Even in the secret state secession conventions, private letters between leaders slavery was the cause mentioned. Like when Georgia politician Henry Benning wrote former speaker of the house and Gov of Georgia Howell Cobb in a private letter "It is apparent, horribly apparent, that the slavery question rides insolently over every other everywhere -- in fact that is the only question which in the least affects the results of the elections."
Or Lawrence Keitt, who said in a secret secession meeting in South Carolina "Our people have come to this on the question of slavery.... it is the great central point from which we are now proceeding, and I am not willing to divert the public attention from it."
Which removes all doubt that it just wasn't something to build public sentiment, or a public rallying point but the true cause.
Of course after the Civil War ended in their defeat, white Southerners attempted to retroactively justify the Confederacy with the ‘Lost Cause’ ideology, an ahistorical narrative that further reimagined the Old South as filled with happy enslaved blacks.
All of a sudden they were trying to build "loyal slave markers", the monuments to prove that slaves were happy and well as slaves. Granted actual former slaves weren't building them. As those have been easily proven to be a false flag with stories of slave uprisings and over 100,000 slaves escaping via the underground railroad, the movement went on to try and rewrite the lost cause again with new things like tariffs, or turning a state wanting the right to enslave blacks to just "states rights".
Speeches got cut off and shortened, so in Lee's speech where he says "“In this enlightened age, there are few I believe, but what will acknowledge, that slavery as an institution, is a moral & political evil in any Country." But then tried to wash away the following line of "The painful discipline they are undergoing, is necessary for their instruction as a race"
Doesn't sound so good anymore. Like when someone says "I know murder is morally wrong.... But I feel it is necessary for me to keep murdering". Intentionally losing the 2nd half of that quote is quite a lie.
Luckily, now instead of having to head to a major library and hope they have some of those source documents, we have online archives. So when a lost cause lie pops up, it can be countered with actual source fact from the secessionists own mouths and writing instead.