You've said Southern exports and the money they generated were at the root of the conflict. What do you think those exports were? Cotton. Southern leaders said Cotton was king and it could win them independence and empire. So why is it suddenly not important? If everything secessionists said about cotton over the years was true and everything they expected cotton exports to bring them was possible, any US government at war would be stupid and negligent not to stop the cotton trade. Or do you really expect that the CSA could do whatever they wanted to hurt the USA and the USA couldn't strike back at them? Are you really that thick? You may even be one of those people who thinks we fought WWII because we wanted to destroy our economic competitors.
But what the blockade did do is scare away normal trade, and funnel the vast bulk of the existing trade to New England.
What a blockade does is block trade. What else is a blockade supposed to do? But what would New England have to do with it? Most of America's exports once the cotton trade bottomed out would have been things like grain and maybe metals or timber. Just what we were importing, I don't know, but New York (with its access to the products of the Great Lakes States) would have been the main port. It's confusing. You spend months railing against New York. Now all of a sudden you hate New England more. "Boo, evil New England" pops up all over the place, and New York City is forgotten.
As Charles Dickens noted, Millions acquired by the North and Lost by the South. It was only a question of where those Millions would end up.
Charles Dickens was no economist and he really hated Americans. He wasn't here in the US and was just talking off the top of his head.
It would create them wealth, which over time equates to power.
So why is it suddenly not important?
Hold up. Don't go running off with the cart before the horse. I didn't say it wasn't important. It was very important economically it was of little to no importance militarily.
Interdicting normal trade between Europe and the South would have little or no immediate military effect. The combatants in the South were already there. Sufficient weaponry to fight was already there.
What the blockade did was to make sure that the European Traders were scared away, and not because they would be carrying men or munitions, but because Lincoln did not want them to develop a serious stake in Southern Trade.
He did not want to allow economic competition to become established. Again, that is the *ENTIRE* reason for the war. It is that threat of Southern economic competition and it's commensurate loss of profit and industry that the Union couldn't stomach.
What do you think Protectionists do? They PROTECT! They even implement this protection with Navies, with Armies, and with Guns. It's the same policy, just by other means.