|For the city as described in the canon games, see Chicago.|
|The following is based on Fallout Tactics and is not canon.|
Sometime after the defeat of the Master in 2162, the Brotherhood of Steel dispatched at least one airship east, to track down the remnants of the Unity super mutant threat. The airship crash landed near the ruins of Chicago. The survivors initially organized themselves into a new detachment, but by 2254 they had gone rogue, cutting all contact with the larger Brotherhood.
Meanwhile, the surviving members of the first expedition thrived outside of Chicago. Far from the elders in Lost Hills, a new Midwestern Brotherhood chapter was formed. It diverged heavily from Brotherhood orthodoxy, incorporating many small towns, protecting the locals from raiders and other threats, and distributing advanced technology. They also began openly recruiting not just wastelanders, but ghouls, super mutants, and even talking deathclaws. By 2197, they had firmly established a neo-feudal society around Chicago. The technology-worshipping Reaver cult, based in Newton is also an organization located here.
Chicago is mentioned only in Fallout Tactics.
Behind the scenes
Chicago is a real world city of the same name, in the Midwestern United States.