Your post explains that you have not promoted the Morrill Tariff as a primary cause of the war. I hope you'll forgive me for the misunderstanding.
I've come to value your posts on this and other topics because they include original sources to make points. You don't write editorial opinions.
Certainly economic policies advocated by first by Northern Whigs and later by "Black" Republicans grieved wealthy Southerners. The protective tariff is an early example of wealth redistribution in U S politics.
If we're going to continue this topic, we should consider the impact of protective tariffs on the post-war United States.