Timeline

2000
A series of catastrophic earthquakes smashed the cities and countryside of San Andreas. In the aftermath, the whole state found itself separated from mainland. Fear and selfishness roamed free, pushing society into chaos. In the heart of San Fierro, one of the largest cities of San Andreas, government-sponsored Zombotech Corporation was researching biological weapons in its underground facility. The labs were heavily damaged by the cataclysm and a deadly infectious agent escaped in the streets. While emergency services struggled to contain the disaster and minimize collateral damage, viral death was spreading unnoticed.

2001
The Establishment evacuated survivors of the outbreak to the barricaded city of Las Venturas but infection soon spread inside the fence. They nuked the city and placed San Andreas under strict military quarantine. It was quickly re-organised as the Territory of San Andreas, ruled by martial law. Nobody gets in, nobody gets out. They dubbed the disaster as the ‘Incident’ to minimize its gravity, media soon went silent and survivors were forgotten.

2007
Six years passed and things have not become better. Survivors picked things up from the point where the government left them and started to get organized. This is a tough new world, populated with the full spectrum of humanity: resilient survivors, vicious bandits, cannibalistic raiders, oppressive military forces and the rest of the loons. No line between good and bad was ever so ill-defined! Militias fight for supremacy, idealists work to maintain civilization and everybody else just struggles to survive another day in an increasingly suffocating world.
 * S﻿an Andreas is ruled with an iron hand by Governor Skinner, who took office only six days after the Incident. His armed forces fight to control the territory, herding men into the new Refugee Camp. 
 * Resources are scarce and many dropped the last remnants of morality when they faced starvation. Violent clans and factions fight over the remains, establishing turfs or just trying to stay alive. The Civilian Defence Force militia has declared Red County a free zone, controls it from the Dillimore stronghold and is fighting against the government to secure its claim.
 * As it became evident that the﻿ government has no rescue plan for them, despair started to crumble the minds of the few sane left. All attempts to flee San Andreas are met with airstrikes. But there are ways to escape this place...

2018
Monocorp is granted a full mandate to bring back the rule of law and reorganize day-to-day life in the Territory of San Andreas. The Secured Enclave of Los Santos (SELS) is created and a huge wall is built around the Downtown district to protect the local Monocorp Headquarters from the rest of Los Santos neighbourhoods. The New Order is instated in San Andreas. Rescue-01 manages the flow of people from the refugee camps to the city of Los Santos.

2020
Under Monocorp's rule, Los Santos starts again to look and behave like a normal city. The Peacekeeper Corps control the enclave and maintain the New Order while refugees are slowly settling in. Small bussinesses start to flourish again, just like the criminal underworld does. A new currency was introduced by Monocorp: the monokredit, called 'credit' or 'K' for short. There is a limited but steady supply of imported goods from Mainland. Monocorp is currently the largest job provider in San Andreas, but there are numerous other ways of making a living, legal or not.
 * Gangs were mostly pacified and seem to do well in this new environment. Less people dead means more customers, after all... They handle drugs, racketeering, smuggling of illegal cargo, vehicles and men but also legal bussinesses like transport of goods over the state. 
 * Rebel separatists are still holding a claim over the countryside: The unrecognized Free County of Red (FCR) occupies strongholds in Red and Flint Counties and is starting illegal farming operations all around the state. They are in open military conflict with Monocorp and the mainland government.
 * In the aftermath of Operation Strict Resolve conducted by Recon Marines elements deployed from the Mainland in 2018 (a ruthless military campaign which aimed to squish all armed resistance in San Andreas), Raiders became less vicious and more discrete. They still plague large swaths of land, especially in the barren lands up north, and roads across the state are never safe due to highwaymen and 'asphalt piracy'. However Raiders mostly renounced their more extreme habits (while some clans are reportedly still using cannibalism as a rite of passage for their members).