If they had been poor, Lincoln would have waved them good bye. Since they were paying 75% of all federal tax revenues, nobody was going to let that cash cow go without a fight.
Nobody was going to let them go period.
It was a nonstarter to begin with and the Democrat parties’ desire for a racist slave empire cost the country almost 700,000 deaths and in dollars and cents, the U.S. government estimated in Jan. 1863 that the war was costing $2.5 million daily. A final official estimate in 1879 totaled $6,190,000,000. The Confederacy spent perhaps $2,099,808,707. That is approximately $226,395,504,868.00 in today’s money.
So much for the large percentage of federal taxes collected in the South. The entire Federal Budget in 1860 was only $170 million. That would have funded less than three months of expenses in the Civil War.
There was simply no way that the industrial North would allow the Southern half of a continental country just walk away.