I was really wondering, what would Chicago be known for during this time period in fallout? is it just there, or is there like a main faction there or what? i haven't been exposed to much canon, so the answers would be much appreciated.

Before you post a question, you should take the time to review the wiki to see if the info there answers your questions. Chicago was the setting of fallout tactics. Takes place in 2197, the User plays as a bos soldier. Down town Chicago was hit by many nukes durring the war but much of the city is still standing. There is a bos bunker, enclave outpost and tribals on the outskirts of the city. It is also mentioned in fnv as the original starting point of ed-e.
Some people in the forum suggest this should be the location of fallout 4. My personal theory is that the enclave controll the area with the abundance of pre war factories to run there war machine. With the ncr wiping out the enclave on the west coast and the bos defeating them in the east, Chicago could be the last area of the country that the enclave controls.