"Sorry, Pea, but I don't see one bit of oppression there"
You can say that but the speech is there, recorded, and specifically states the concerns. You can label it as vague but it does not make it so.
The agitation and threats have been recorded. Your Neo-historianism does not change the facts.
"And I thought you were of the school that claims slavery had nothing to do with the war."
Wrong again. I have said that abolitionist activity was one of the many irritants that led to secession, but war came for a very different reason.
The abolitionist "agitation" as you call it represented the views of a very small minority on Northerners and most certainly not the policy of the Federal Government. There was not a single instance of "oppression" by the Federal government alleged by the seceding states.
If the South chose to "secede" from Horace Greely, fine. But they had no justification for rebellion against the United States.