Civil War is a story mission in South Park: The Fractured But Whole.
Plot details follow.
You get an alert message from Coon. He tells you to confront the Freedom Pals in the Main Street of South Park, head there and do so. Once there, a fight will start between Coon and Friends and Freedom Pals. Once the fight is over, it is revealed that The Coon stole Doctor Timothy's cellphone for some important intel.
Follow The Coon to Main Street, or just use the fast travel point outside to get there easily. We learn now why Craig and Tweek broke up. Tweek left Coon and Friends to join the Freedom Pals, and Craig didn't go with him.
Note: Try to take out Wonder Tweek first. His long-range AOE attacks are a real pain and inflict your Allies with Shock.
Your next goal is to find a girl with a dick tattoo, who apparently has information about the cats in town. Now continue to Homeward Bound, so you can prepare for the night ahead.