I know this has been a topic for a while, but I think a balls to the walls- guns spilling out of every corner event series set in the USA would be cool af. I think, for rebels and Union, cool stories about not only the concept of personal liberty, but also how draining the paper trails of bureaucracy can be on a better formed force can be told, as IRL, we have more guns than people here in the states, and plenty of people would go up in arms the moment the Unions intentions were clear.
I also think City 1 (New York) would be a cool place to see. (If we ever went back to City RP)