[BroJoeK]

quoting BJK: "First, your "$700 million per year" is just a figure from your own imagination, not from political discussions in 1860."

DiogenesLamp: "Well the number is easy to explain.
200 Million per year in trade with Europe, and 500 million per year in trade with Northern manufacturers."

And yet... we know exactly what actually happened when your "700 million per year" was deleted from Union GDP and tariff revenue numbers.

Union GDP rose from:

1. $4.4 billion in 1860, then rose 5% to
2. $4.7 billion in 1861, then rose 29% to
3. $5.9 billion in 1862, rose 31% to
4. $7.7 billion in 1863, rose 25% to
5. $9.6 billion in 1864, rose 4% to
6. $10.0 billion in 1865

Union tariff revenues fell 25% in 1861, but then rose (rounded):

1. $53 million in 1860, fell 25% to
2. $40 million in 1861, rose $9 million to
3. $49 million in 1862, rose $20 million to
4. $69 million in 1863, rose $33 million to
5. $102 million in 1864, fell $17 million to
6. $85 million in 1865

In the meantime, US cotton production/exports also fell but then rose after the war:

1. 4.9 million bales (~460# each) exported in 1860
2. 3.1 million bales in 1861,
3. 0.6 million bales in 1862, to
4. 0.01 million bales in 1863, to
5. 0.03 million bales in 1864, to
6. 0.02 million bales in 1865, to
7. 2.3 million bales in 1866, to
8. 3.1 million bales in 1870, to
9. 5.8 million bales in 1880, to
10. 7.3 million bales in 1890

So, there is no doubt that the loss of the Confederate states' economy, especially cotton, was a blow to Union GDP & tariff revenues, but it was nowhere near the disaster your "$700 million per year" suggests.

This 1880 map is from the last link above, showing US cotton production, exports and imports through 1880, in dollars, not bales.
If you go to the last link above you can zoom in to see those actual numbers.
For numbers of cotton bales, I've used the figures from the second to last link.

[DiogenesLamp]

And yet... we know exactly what actually happened when your "700 million per year" was deleted from Union GDP and tariff revenue numbers.

Beside the point. The *FEAR* of losing that money is the *CAUSE* of the North invading the South.

Also, they started faking financial data during the Civil War. Greenbacks were just fake money.