Goal was to balance green and blue induvidually and rolled up to your district. Districts members of a loose confederacy. Students wrote to the instructor each class meeting with what they were doing. Trade, grow, invest. I don't remember all the options, but ag produced green and industry blue.
By the end of the term, a district with a sea port held a landlocked one hostage by denying access. The southern districts discovered an animal that could do agricultural work and proceeded to enslave them. Don't remember the exact course of events, but this triggered a succession.
We were shocked to discover the parallels with colonial, confederation, csa, etc. Mr. Thompson made it obscure enough junior high students didn't pick it up, but close enough that we recognized ourselves when the explanation came.