I recall hearing that the rich people of the South also owed Northern banks $200 million and that they (or some) saw Secession as a way to nullify those debts.
I’m not sure how much something like that may have also fit into the motives.
I don't know how much my history buff friend had actually researched about this, but it would be fascinating to find out how many banks actually owned how many slaves when the war broke out.
There weren't very many rich people in the South at that time. Even most of the 379,597 slaveholders were not rich.
I think that's right and Confederate governments did quickly outlaw debt payments to Union banks.
But it was not among the reasons given in any Reasons for Secession document.
How then can we claim it was a "real reason" as opposed to officially stated reasons?
I think no honorable person would openly admit scheming to renounce their debts, but if that were the consequence of a Union assault on the very basis of their economic prosperity (slavery), well... then... so be it.
So put yourself in the shoes of a Southern planter who owes money to Union banks for purchase of your land, equipment & slaves.
You well intend to honorably pay your debts, but what if now, those same Northerners who loaned you money are now voting for "Black Republicans" who wish to abolish slavery and thus the basics of your economic way of life?
But it began with the perceived assault on slavery, the economic consequences followed.