I think your article is unclear, which is why I'm reading a lot of comments saying it was about slavery. I like your quote here:
"By and large, the North had no objections to enslavement of blacks, they simply had no economic use for the practice themselves. "
In other words, fake news from the South led the South to pick a fight with the North, who would buy cotton from the South, disregarding it came from slavery, same way we disregard blood diamonds and Nike shoes being created by imprisoned Uighur slaves in China.
It became about slavery later on during the war. But fake news was the real cause.