[BroJoeK]

DiogenesLamp: "Slavery was producing 72% of the total revenue for the Federal government in 1860.
It had been producing the bulk of the tax revenue since the 1820s.
Pretty much everything connected to government during this era was paid for by the slaves."

Or so it was claimed by pro-Southerners at the time, based on the value of Southern exports in relation to Federal tariff revenues.

But a truer picture is much more complicated because, for starters, Southern exports were not 100% based solely on slavery.
Southern exports also depended on massive "imports" from the North of everything from capital (bank loans) to industrial products like railroad and telegraph equipment, to ships for freight, to farm tools, household goods, clothing and some food.

Because of this, foreign imports (and so Federal tariff revenues) did not flow into the South in proportion to their exports, but rather were sold everywhere in the US, depending on each region's relative incomes.
Wealthier cities imported more foreign goods, and so paid more of Federal tariffs, while poorer areas imported less.

Which brings us to the question of where, exactly, was the nation's wealth, per capita -- North, South, East or West?
The answer may surprise you, it did me.

As reported here, the average annual per capita income (APCI) in 1860 of various regions was:

1. West South Central (Texas, Louisiana, Arkansas, Oklahoma) = $189 APCI X
   Population = 1,802,667 = $331,690,728 = 8% of US GDP

2. Northeast (from PA to Maine) = $183 APCI X
   Population = 10,594,000 = $1,938,751,044 = 49% of US GDP

3. East South Central (MS, AL, TN, KY) = $89 APCI X
   Population = 5,203,003 = $463,067,267 = 12% of US GDP

4. North Central (Ohio to Iowa) = $89 APCI X
   Population = 7,773,820 = $691,869,980 = 18% of US GDP

5. South Atlantic (Florida to Delaware) = $84 APCI X
   Population = 5,289,623 = $444,328,332 = 11% of US GDP

So the Midwest and Southeast had roughly half the per capita income as the Southwest and Northeast.
Overall, we see 31% of national GDP in the South, 69% in the North and West, and that is likely also the distribution of tariffed imports, and therefore of Federal revenues in 1860.

We should also notice, the claim of "72% of Federal revenues" allegedly "paid for" by "Southern Products" can only be made by exaggerating Southern exports and minimizing exports from the North and West, especially by not counting California gold or Nevada silver as Northern exports.

[x]

+1

[DiogenesLamp]

Or so it was claimed by pro-Southerners at the time, based on the value of Southern exports in relation to Federal tariff revenues.

Easiest way to comprehend it, and close enough to being correct as to make little difference.

But a truer picture is much more complicated

Yes it is, because the tariffs varied from one type of product to another and from various times they were enacted. It is a mess to try to unpack everything bought and sold at the time, and to try to assign a value of gain/loss to the artificial markets created by the Federal government tampering with market forces.

But one thing is pretty clear, the whole thing served as a money pump to move money from the South into the North.

especially by not counting California gold or Nevada silver as Northern exports.

As I told you before, you can't count specie as "trade." You keep trying to put gold and silver into the equation of trade, because it makes your numbers look better, but specie isn't trade.

The product swapping (you know, actual trade) between Europe and the US was 72% from the South, and 28% from the North.