In 1863, a time pirate crash-landed in Mississippi carrying a futuristic bioweapon. He was later exposed to the virus and spread it to numerous Confederate soldiers, causing symptoms comparable to zombies. This interfered with General Ulysses S. Grant's efforts in Mississippi when zombified soldiers killed Henry Scott, causing a time aberration. The Legends arrived in Mississippi to fix the aberration. Jefferson Jackson and Amaya Jiwe infiltrated the Collins Plantation to complete Scott's mission. The duo also freed all the slaves and burned down the plantation during a zombie attack. Sara and Nate helped General Grant destroy the rest of the zombie horde. Jax gave General Grant the Confederate plans, fixing the aberration.
In an alternate timeline, the outbreak of confederate zombies ensured that Henry Scott's mission failed and that the Union lost the Battles of Champion Hill and Vicksburg. Due to these events, the Union lost the Civil War and the United States split into two nations with Mississippi a part of the Confederacy.