Following the dissolution of the United States as a political and national entity, it became the duty of the states to retain themselves, support their infrastructures and maintain things such as law enforcement, health care, and civil defense. Some states did this quite well, such as the Republics of California, and Texas, as well as the Commonwealth of New England, and the New York City-State. Others faired much more poorly, such as the states of the Gulf Coast, Great Plains, and the Rockies. Michigan survived the second Great Depression somewhere in the middle of the pack.
The Pontiac Arcology sits as the seat of the Government of Michigan. The structure is 800 meters tall, houses over 150,000 residents and is the hub of the local communications network. Rail lines have been re-established as a means of personnel transportation for people. The main lines from the the railhead near Pontiac to the allied cities of Lansing, Grand Rapids, Monroe, and Old Detroit.
New Detroit is the name given to a ramshackle collection of half finished buildings, and the foundation level of Michigan's second Arcology, which was never finished. New Detroit is a hotbed of thieves, murderers and is the home base of several prominent gangs, such as the Michiganders, the UAW, and G'M. The Michiganders are typical raiders with piecemeal weaponry, no armor, and many sport neo-native american dressing. Most of this is innaccurate, but few argue the discrepancy of Apache style beads and feather warbonnets and mohawks when they are about to be scalped. The Michiganders have numbers, and respect strength in numbers and when not on the warpath are somewhat civil. They also have adapted fairly well to Michigan's climate and restoring wildlife. The Michiganders have retained herds of domestic horses, and as such are an odd mixture of 75% Neo-Indian and 25% Cowboy (culture)
The UAW has nothing to do with it's namesake other than their HQ squatting in the middle of a UAW hall. The UAW does have a number of functional vehicles as well as distilling operations supplying them with ethanol fuel for their automobiles. UAW raids happen from vehicles, with motorcycles outnumbering cars and trucks 3 to 1. Machine guns, molotov cocktails and other improvised explosives are the norm. UAW are known slavers, and while technologically advanced compared to the Michiganders, they are violent to a fault. The G'M (pronounced Jim) are the smallest of the gangs and have a functional, if unpowered factory complex under their control. When there is enough light for the solar panels to operate, they do manufacture a few things, but production is scattered and unorganized. G'M tend to have scavenged laser weaponry and modded power armor. The Pontiac Arcology tolerates the Michiganders unless they start raiding, have a tenuous peace agreement with the UAW (until it can muster man and firepower to wipe them out) and considers the G'M a pointless waste of energy, with their worship of the factory bordering on religion.
The top level of the Pontiac arco is a staging area for post-war Zeppelins. The rigid airships run on solar panels on the top of the gas envelope, and small ethanol powered engines. Transit speed is slow, 60 mph, but reliable and compared to land travel beyond the patroled rail lines across the state, safe. Most of the airship travel is to friendly arcologies south of Pontiac, such as the Chicago Arco-Plex, or the Arcos that formed the Commonwealth of New England. The airships travel high and largely silently, and firing at them is a good way to something unpleasant dropped on you. Most airships have a cadre of snipers to defend them from small ground targets.
There are dozens of communities that trade with Pontiac, exchanging food, ethanol, and other goods to the Arco for finished goods, luxury items and tech. The aerial complex atop the Arcology provides for a radio and television broadcasts, as well as a wireless phone network. Power supply is up to the communities, which tend to use small windmills, waterwheels, and other primitive non-combustion systems to generate electricity.