Strong circumstantial evidence supporting piracy as a cause of the Civil War.

[Solvedit]

We are not discussing what could have happened, you linked the demise of pirates, navel propulsion and weapons technological development internationally to a mostly land war within one nation.

While I do see the technological discrepancy from North and South as a factor in that war, I do not see the factors you brought up as having anything to do with it.

Please explain it to me.

Suppose the pirates may have moved to the South after propeller-driven steam frigates destroyed their ships and port facilities in the early 1840s because there was no room in their home country to support them by giving them legitimate work.  Their home countries also lost the foreign income they had gotten from piracy. There would have been a famine unless all the people who had been supported by the pirate economy also left.  

Suppose they have returned to piracy because the US has way more coastline to hide in than, say, the Barbary States, and provided they kept their hands off USA shipping, maybe the steam frigates chasing them had to come from much further away and had to quit when they got to within 12 miles of the coast.  

If any of that happened, the nations of South America and Europe may have been offended that the USA wasn't doing enough to prevent people in their borders from practicing piracy, so they may have encouraged the South to rebel in the hopes that the US would have to defeat and occupy them.  

The US was uncommonly generous with the revolutionaries after the war.  If it had been like many revolutions, government officials would have been arrested and jailed or executed and strict control would have been extended over the people.