I guess the whole history of the game got wiped out when the forums changed. In a nutshell, it's an alternate history scenario. The South has lost the war. Booth goes to assassinate Lincoln, but a guard redirects the shot and instead of killing him, he loses his left arm. Embittered, instead of an olive branch, he orders the Federal military to put a boot on the South's neck.
The whole situation develops into a conflict not unlike the Israeli Palestinian conflict. The Federal government and Southern Nationalists have been at odds ever since. The Federals have managed to isolate even people who most likely would have been loyal.
The South has broken into several factions:
1. Southern Nationalists who only desire independence. They are organized into illegal militias. Many Southerners related to the original leadership have been put into Federal Detention Camps and all Southerners are considered 'residents' rather than citizens. They have limited rights and must present their green resident cards if stopped by Federal authorities.
2. The Black Liberation Movement, desiring a seperate state and independence for persons of color. The movement is supported by most Southerners. BLM members fight alongside Southern Nationalists and reject the Federal government for having broken promise after promise to the since the end of the war.
3. SOG: The Sons of God, madmen who demand an eye for a eye and tooth for a tooth, showing no mercy to Federals at all. They are terrorists and commit atrocities on a regular basis. (Think VC, Hamas Hezbollah)
The Federal government has declared the entire former Confederacy the "Southern Military Occupation Zone" or more commonly "The Zone." Federal troops call the South "Bloody Dixie".All major cities in the South are occupied by Federal troops and the dreaded Federal Internal Security Agency (FISA) runs the detention camps and spies on Southerners through secret agents (think the Gestapo). Anyone found to be related to the former Confederate leadership, even to this day, are permanently detained in the camps (think Palestinian refugee camps) and the camps are often the source of Uprisings resulting in more Federal troops being brought in.
The US is a regional power, but not the world power it is in our timeline. Many things are different. The Russian Czars put down the Bolshevik Revolution and still run Russia. Czarist Spetsnaz (mostly based in Cuba) supply and advise Southern Nationalist militias.
Now you're up to date.