OK, I have to give credit to Sessions for saying this:

Jeff Sessions to the Union League, marking Lincoln Day: “Slavery was the cause of the war. It was not states’ rights or tariffs or agrarian versus industrial economies….The cloud, the stain of human bondage—the buying and selling of human beings—was the unsolvable problem.” pic.twitter.com/eZCC7woODu

— Yoni Appelbaum (@YAppelbaum) February 12, 2018