On March 11, 1957 a gang of Chicago teenagers assaulted and killed a sixteen-year-old African American boy, Alvin Palmer. Many of the members of the 'Rebels', a street gang from the Back of the Yards neighborhood were Polish Americans and members of Sacred Heart Parish. The paper looks at both the gang and the neighborhood in an attempt to see the effects of assimilation on Chicago's Polonia. Chicago's Polonia had a long established history of juvenile delinquency. Many Polish American youth were members of mixed-ethnic gangs as they became assimilated into the life of Chicago's streets. The State's Attorney, Benjamin Adamowski, quickly brought charges against the members of the Rebels involved in the Palmer murder and called for their execution. The randomness of the event and the character of the Rebels involved in the murder sheds a good deal of light on Chicago's postwar racial conflicts.