The night life in Chicago is always up and living two particular areas are University Village and Wrigleyville. I do not really know much about the night life in Chicago since I am not of age but these two cites will explain everything http://www.bleachernation.com/chicago-cubs-resources/wrigleyvilles-best-bars/ and http://www.yelp.com/search?cflt=bars&find_loc=University+Village%2C+Chicago%2C+IL, these cites will allow you access to all of Chicago bars.
The way to these bars is simple as well it will be going to other a Bears game or a Cubs game same directions.