With magic money produced by their fairy godmothers.
This idea you have that people can "buy" stuff when they don't have money is alien thinking to me.
Things can only be bought with money that has to come from somewhere.
The money to purchase 72% of these European goods came from the South. It did not come from magic money trees or fairy godmothers in the North.
So cotton exports was the only way to make money in 1860? Good to know.