My post 108 does support your comment about the greed of Northern businessmen. When separation occurred Southern goods were going to be shipped directly to Europe on their ships. Northern shippers, bankers, insurers, and exporters were about to lose the majority of their income.
Goods returning were headed for Southern ports where the import taxes were half that in the north.
With over 80% of the US Treasury being funded by tariff revenue, the government was broke, and in need of loans and changes in the way it obtained revenue.
Yes, northern businessman were concerned. They were howling about their future, pushing for their own secession in NY, and sending some Governors to push Lincoln into war.
Some confuse greed with survival. It was the survival of
Lincoln's political party that motivated him to use the military instead of emancipating the Southern states.
Lincoln's political philosophy, which he acquired from his Mentor Henry Clay, was "Mercantilism." (Which has nowadays has evolved into "crony capitalism") Lincoln's strongest supporters were among this group who would be most hurt by an Independent South.