Two items: California gold and Nevada silver.
They balanced everything quite nicely.
But please remember: when I say cotton was 50% of US exports, I'm including specie.
When DiogenesLamp & others say "Southern products" represented (tak your pick) 75% or 80% or 90%, they exclude specie from their calculations and add in a lot more than just cotton.
But it does bring up a curious question. If the specie is coming from California and Nevada, then why is almost all the import money ending up in New York?
I was referring to Lampie’s need to have imports and exports balance, as part of the proof that Southerners paid the vast majority of the tariffs. Clearly there were more imports than exports throughout the antebellum period. Of course he just blows it off as “roughly equal.”