The state of Mississippi was the 32nd most populous and 32nd largest state in America before the outbreak
Nothing is known about Mississippi during the outbreak. It can be assumed that during the initial stages of the walker epidemic, it followed the example of California, with state and local police being among the first responders, with these first responders being joined by military units if and when a state of emergency was declared, or when Operation Cobalt was put into effect.
Morgan arrives in Mississippi by accident, after falling asleep in the back of a truck while taking shelter from a storm in Texas. When he wakes up, he finds himself at a truck stop and comes across two survivors, Wendell and his sister Sarah. While claiming to be compassionate truckers that would aide survivors by dropping supply boxes alongside roads within a ten miles radius. In reality, they stole the truck from a man named Clayton who had several trucks loaded with supplies that he and his group would deliver in good faith.
After resting for a while, Morgan leaves and helps a man named Jim who attempted to fend off a group of walkers with a sack over his head. After helping him, the pair run into Sarah and Wendell who are revealed to be the ones who kicked Jim out of his brewery and put the sack over his head after refusing to give them his recipe for beer. Jim agrees to help Sarah and Wendell craft beer to spare him and Mogan's lives. Morgan later convinces all three to reconcile their differences and search for the rest of his group, promising they'd venture to a settlement in Virginia for refuge in exchange for their assistance.
After regrouping and escaping an antagonistic woman, the group returns to the truck stop only to find out that Martha tainted the water with anti-freeze. Fortunately the group is saved by Morgan who raided Jim's brewery for beer which nullified the effects of the poison.