I'm half being a smart azz... and half not. I don't think a protracted insurgency could work in this country then or now. Our women are not, and have never been, totally subjected like they are in Afghanistan and Iraq. They'd eventually get tired of living the life of an insurgent's wife and start ratting us out, denying sanctuary needed for an insurgency to succeed.
As to the south and the strategy they chose... I’m sure they thought they could lick the north in conventional warfare. They wouldn't have tried if they didn't.
