The Secession War was a military conflict fought two hundred years before the events of Dead Space between the Earth Government and Sovereign Colonies. The number and length of campaigns is never revealed. It's primary theater is believed to be at Earth.
The war saw the two bodies of government engaged in an extensive conflict for control of human space. However, the colonies’ dwindling resources and public support[1], in conjunction with the Sovereign Colonies Armed Forces expedition to Tau Volantis saw the eventual end to the Colonies. EarthGov defeated the Sovereign Colonies and maintained control of Earth and the colonization of planets[2][3].
Trivia
- In the beginning of Chapter 3 upon entering the Roanoke if the player immediately exits, Isaac will call Norton asking about S.C.A.F. and the flotilla and Norton will start talking about the secession war and give his opinions about S.C.A.F.