Salem is the capital city of Oregon and a main location featured in Life After Death. During the beginning of the zombie outbreak, it, like most other large cities in the United States, was put under military occupation in order to defend the common people from the zombie virus. However, as with most of the cities under military occupation, the commanding officers ruled with an iron fist and enforced strict, unfair, and in some cases abusive rules to keep citizens in line.
A portion of the military occupying Salem, however, despised this cruel practice, and after several weeks of their occupation, 86 soldiers, including Corporal Jonathon Hamilton, took part in a coup d'etat and took control of the city from their commanding officers, imprisoning most and killing the handful of rebels who refused to surrender. The new commanders decided to sever their ties with the greater United States military, proclaiming themselves the "Salem Security Unit", or the SSU, and rule their own way, dedicating their time to protecting Salem's citizens and keeping them safe, retracting the rules put in place by the previous leadership.
Before the telecommunication services in the country fell, news of the SSU and this new "military-free safe-zone" in Salem spread throughout the state, with word specifically reaching Dolph and Zoe Gunn, who set out for the safe-zone following the collapse of Seattle, Washington.
However, the safe-zone did not last long, as the SSU gradually began losing members, either to zombies or to rogue groups of survivors. As the manpower of the safe-zone began to dwindle, survivors within the community became desperate, and set out into the "dead-zones" of Salem to find resources for themselves, opting to kill people who opposed them, essentially becoming post-apocalyptic bandits. A group of these bandits attacked a sizable group of survivors in the city led by a man named Edward Harrison, but were mostly fought off, though several of Edward's people ended up getting killed, including Edward himself.
Following this attack, Edward's son, Alvin Harrison, accompanied by eighteen members from his group, counterattacked the safe-zone, killing most of the bandits, and causing many of the survivors and soldiers from the SSU to abandon the community. One of the bandits, Frank Ward, survived the assault and was given a second chance by Alvin, as he recognized the man's strength and acknowledged that his violence came from a place of desperation, a feeling Alvin shares.
Combining his own group's forces with the citizens and soldiers who remained in the safe-zone after his counterattack, Alvin took over the community as it's definitive leader, appointing Frank as his second-in-command, and putting the remaining members of the SSU in charge of the city's defense, captained by Jonathon Hamilton. While the community's size was at this point a shadow of what it used to be, Alvin sought to remedy this by accepting in any survivors who came across them, in an attempt to both save the lives of as many people as he can and add to the community's overall strength, as was the Salem Security Unit's initial goal.