Chicago

Chicago was a city located in Illinois. It was nearly completely destroyed during the Great War and the few that survived the bombs now live mostly in small tribal villages near the former city.

Background
Before the Great War detective Nick Valentine together with his fiance Jennifer Lands transferred from the Chicago Police to Boston to assist the Boston Police Department in Operation Winter's End.

Sometime after the defeat of the Master in 2162, the Brotherhood of Steel constructed airships and dispatched some of its soldiers East, to track down and assess the extent of the remaining super mutant threat. However, a great storm broke the main airship and flung it far from its course. The other airships were torn apart and lost.

The mighty airship was badly damaged. The meteorological disturbances were so intense that sections of the craft were wrenched free of the ship and lost, leading to casualties among those onboard. Even the leaders of the expedition were not spared, with many of them being lost, including Paladin Latham. The survivors managed to keep their battered ship aloft, but eventually, they came down on the ruined city's outskirts. Those who made it clear of the wreck eventually formed an organization called the Midwestern Brotherhood of Steel, which diverged greatly from the ideals of the original Brotherhood of Steel. In time, they established a harsh rule over the towns and villages near Chicago, controlled from Bunker Alpha. The sky over the city is always dark and stormy, and the city seems to be completely deserted.

However, there are suggestions that the Enclave maintains outposts within the ruins. There is also a West Coast mutant population, that the Brotherhood fought (or assimilated). It is also where Tommy recovered ED-E, and after pleading with his father, brought it back to his mother's garage for repairs.

Appearances

 * The remains of Chicago appear only in the Fallout Tactics intro, but not directly in-game. It is the most likely location of Bunker Alpha and the beginning of the main campaign, or if not, it is definitely in close proximity.
 * Chicago is mentioned in conversations with Fallout 3 by Scribe Jameson or Scribe Rothchild about fighting super mutants or by asking about where the rest of the Brotherhood of Steel is.
 * The city is also mentioned in Fallout: New Vegas on a recording found on ED-E during the quest ED-E My Love, hinting at Enclave outposts located there.
 * It is furthermore mentioned in the Fallout: New Vegas add-on Lonesome Road, when the copy of ED-E is telling the Courier about Whitley and his journey to Navarro, to which the Courier will reply, "What's a Chicago?" and "Illin-what? You're making that name up." if they haven't met the Mojave ED-E.
 * In Fallout 4 it is mentioned on the holotape Welcome home!, as well as the source of the Skylanes 1981 flight in Skylanes smuggling manifest.
 * The city is mentioned in notes found at Aaronholt homestead in Fallout 76.

Behind the scenes
Chicago is based on the real world location of Chicago, Illinois, in the Midwest United States.