Well, Orville and Wilber hadn't gotten around to inventing the plane yet. So bombing from 35,000 feet wasn't an option. General Sherman did devastate a broad swath of the confederacy\ during his "march to the sea"
You cannot be a terrorist when you fight an invader in your own country. Thats complete nonsense.
But he didn't open the Howitzer's on Confederate weddings.
There's a difference, I think, in waging total war directed at people's stuff vs. at the people themselves. Or callous disregard of civilians.