Calling it the “Civil War” has developed into a bit of a peeve of mine, because it wasn’t really a true civil war. It was a war between two nation states, and except for areas along the actual border, where you might have seen some brother-against-brother shit, the sympathies one way or the other were pretty clear cut based on geography.
On the other hand, what we call the “Revolutionary War”? That was way more of an actual civil war. Sure, an army from another land came from across the sea to fight it, but it also split colonists on a house by house basis all across the colonies, not just in any one corner of it. There was a lot of internecine battling that was among neighbors only, no redcoats involved. That looks a lot more like a civil war to me.