I've discussed the possibility of an American civil war here a number of times. I recently read a novel regarding that possibility, the novel is titled "American War: A Novel" by Omar El Akkad. Any war is brutal, but civil wars are particularly brutal, because they pit family members and friends against one another. This novel depicts an American civil war from the viewpoint of a girl who matures into a woman. The novel follows her through the years as her family becomes war refugees and they experience life in refugee camps. The author does a good job of describing the horrors of war and how small events can have unintended consequences.
There's not a lot of fast action in the book, it's more of a thoughtful novel. It is certainly not the average dystopian novel. It is a dark novel, but it also demonstrates why ordinary people become terrorists. The transformation of a sweet innocent child into a mega terrorist is sad and gut wrenching. I certainly don't recommend this novel for everyone, but the author creates a believable tale of how civil wars bring out the worst in many people. The novel does make you think and reflect on the evils of war.
It's available at Amazon:
https://www.amazon.com/American-War-Omar-El-Akkad/dp/1101973137/ref=sr_1_1