It would be folly to think that the Northern States did not recognize that abolition would have the same effect on cotton production as taking tractors from wheat farmers today would have on wheat production—which would adversely affect Treasury revenue as well. Without a crop, there would be nothing to tax.
"The difference is so great between the tariff of the Union and that of the Confederated States, that the entire Northwest must find it to their advantage to purchase their imported goods at New Orleans rather than at New York. In addition to this, the manufacturing interest of the country will suffer from the increased importations resulting from low duties.
"The government would be false to its obligations if this state of things were not provided against.
" The New York Evening Post wrote,
"Allow railroad iron to be entered at Savannah with the low duty of ten per cent, which is all that the Southern Confederacy think of laying on imported goods, and not an ounce more would be imported at New York; the railways would be supplied from the Southern ports."
The Philadelphia Press said,
"Blockade Southern Ports. If not a series of customs houses will be required on the vast inland border from the Atlantic to West Texas. Worse still, with no protective tariff, European goods will under price Northern goods in Southern markets. Cotton for Northern mills will be charged an export tax. This will cripple the clothing industries, and make British mils prosper. Finally,, the great inland waterways, the Mississippi, the Missouri, and the Ohio Rivers will be subject to Southern tolls".
These commentaries were telling the truth of late March, 1861.
And without a tax they couldn't run their precious federal government; disHonest Abe said so.
In 1860, no Northern state -- none -- called for abolition of slavery in the South.
What Northerners then wished was to prevent slavery's expansion into western territories and even into Northern states themselves.