A modern civil war will not be fought on battle fields. That shit was pointless and stupid in the first civil war (which is a large reason why the South lost, they wanted glorious battles, and the north just burned cities)
No, a modern civil war will look like the mess in Syria or Haiti. It will be disorganized, chaotic, and there will be far too much pointless bloodshed, with no battle lines. Just a bunch of assholes killing people who they disagree with.
Fun fact, this is exactly the sort of situation that Ivermectin was made for. It’s an anti-parasite drug.