I've read the secession documents, all of them. The cause they fought for was to preserve the infernal institution that allowed them to enslave their fellow man.
I know you desperately want to believe that, but only 1.7% of the population owned slaves, and I assure you the vast bulk of them had no input on the "secessionist" documents.
While that 1.7% of the population and it's supporters who may have written those documents might have been fighting for slavery, that other 98.3% of the population was fighting because this massive army tried to invade them.
People defend their homeland, even when their homeland has immoral policies.
If a Muslim army successfully invaded, a hundred fifty years from now people like you would be justifying their invasion because the US supported "Gay Marriage". They know this because they can read it in your Supreme Court Documents.
Not an accurate picture at all. It is, in fact, a deliberate distortion of the truth.