Experts estimate that there are 70,000 to 125,000 gang members in Chicago—a population that, on the low end, rivals Evanston’s and, on the high end, exceeds Springfield’s. Over the years, Chicago’s street gangs have formed two loose alliances: the People and the Folks. According to information from the Chicago Police Department, which tracks gang boundaries, here are the five largest gangs and where they reign.

BACK TO MAIN STORY: Gangs and Politicians in Chicago: An Unholy Alliance »

PLUS: NEW Gang territory vs. 2011 homicides »