Even with your heavily massaged number which includes everything and the kitchen sink thrown in in an effort to make it come out that low, you still have 20 million people in the North producing 50% of the Trade, and 5 million people in the South producing 50% of the trade.
That's 4 to 1 economic productivity from the South to the North.
20 million Northerners were producing only 1/4 per capita of the export value of the 5 million Southerners.
And the vast bulk of the return money still came back through New York. You can pretend that money meant nothing to the Northern Industrialists/ Shippers, etc, but you are only fooling yourself.
They had gotten rich off of slave produced trade.
But by far the biggest loss to not only the businesses, but primarily the government treasury was the loss of goods, i.e. tariff producing items, that would now be direct shipped South from Europe, and bypassing New York, Boston, and Philly. Remember that about 85% of the annual treasury income was from tariffs. If dutiable items even shriveled by 50%, you can imagine the pending damage to the Treasury.
Here is a contemporary article describing this situation:
“GOODS ENTERING FREE AT ST. LOUIS.
The St. Louis Republican, of the 23d says: “Every day our importers of foreign merchandise are receiving, by way of New Orleans, very considerable quantities of goods, duty free. The goods are landed at the port of New Orleans-no Custom-house notice is taken of them-no bonds are executed for the payment of duties on their arrival there; and on many articles the saving of one half the duty only, would afford a handsome profit. If this thing is to become permanent, there will be an entire revolution in the course of trade, and New York will suffer terribly. Our merchants have capital enough to justify them in making their purchases in Europe, and shipping to New Orleans, and in that city, because of the difference in the tariff, goods can be bought cheaper than in New York. With these advantages, we shall be able to sell cheaper than any other city in the Valley of the Mississippi.”
~Harper's Weekly, April 6, 1861.
You can see very clearly how vulnerable the entire shipping empire of the North was upon secession, and the fear these people would have.
First, remember the question is: how much did Deep South exports contribute to paying Federal revenues?
The answer is: all things considered, roughly 50%, period.
The second question is: what percent of the population raised all that cotton?
The answer is: fewer than three million Cotton-South slaves raised it and they accounted for less than 10% of total US population in 1860.
DiogenesLamp: "That's 4 to 1 economic productivity from [slaves in]the South to the North."
Right, in 1860 Southern slaves were amazingly productive and profitable, which is why their price at auction kept increasing throughout the 1850s.
That alone explains why Southern-slaveocrats were so, so anxious to protect their $4 billion investment in slavery.
However, by 1860 Northern productivity in industrial products was also increasing rapidly, some of which found its way into US export numbers, but most Northern produces were for domestic consumption, especially in the wealthy South.
DiogenesLamp: "20 million Northerners were producing only 1/4 per capita of the about the same export value of the 5 million Southerners three million slaves. "
There, fixed it for you. Sure, no problem, you're welcome.
DiogenesLamp: "And the vast bulk of the return money still came back through New York.
You can pretend that money meant nothing to the Northern Industrialists/ Shippers, etc, but you are only fooling yourself."
But I've "pretended" nothing.
Cotton exports were absolutely important in 1860 (50%), but in 1861 Northerners quickly learned how to survive and prosper without them.
So cotton was not as important as Southerners of the time and DiogenesLamp liked to imagine.
DiogenesLamp: "They Southern slaveocrats had gotten rich off of slave produced trade."
There, fixed it for you. Sure, you're welcome.