The Successor States

The Successor States were a group of short-lived polities that emerged out of the chaos of the Terran Civil War

Origins
After the collapse of the Terran Federation that followed the coup of 2240, the newly created Terran Confederation was unable to get the remaining "rebel" colonies to agree to join it.

Many of the colonies banded together as a loose alliance, known as the Independent Systems Alliance (or ISA).

Another,smaller group of colonies banded together as the pro reunification Foundation Republic.

Finally a number of colonies remained fully independent.

States
The Terran Confederacy was the direct successor of the Terran Federation and based on Earth and Mars. The Confederacy started off as a sort of oligarchic state with a strong military component. However during its brief history it moved to become a military Junta.

The Independent Systems Alliance (ISA) was created by a loose alliance of colonies that resisted the Terran Confederacy, whom it regarded as an illegal state. The ISA had a simple, fairly weak form of central government. Due to its weak constitution on member states, many ISA colonies drifted away.

The Foundation Republic was a more coordinated but less confrontational regime that was founded on the Frontier. The Chan political dynasty put a lot of time and money into supporting the new state with the ultimate aim of reunification, an aim it was able to realize.