- [Narrator] July 27th, 1919, a hot summer's day along Chicago's lakefront, a day when the racial tension detailed in Farrell's novels spilled over into real life.

- Chicago was primed for conflict.

You have African-Americans coming in on the heels of the great migration looking for jobs and opportunity.

- As the Irish are returning home from World War I, they're coming with new hopes and aspirations for an improved life, only to find that African-Americans were in their jobs.

And they felt like this was an encroachment on their territory.

- So the fuse was lit, so to speak.

- [Narrator] A group of black friends, including 17-year-old Eugene Williams, launched a homemade raft into the waters of Lake Michigan.

- The lakefront was just as segregated as every other place within the city of Chicago.

Unfortunately, without their knowing, they'd started to drift over to this white designated part of the lakefront.

- [Narrator] When the boys crossed, the invisible boundaries separating the segregated beaches, a white man on shore, 24-year-old George Stauber, began pelting them with stones.

- They would duck down and pop back up and grab back onto the raft and Eugene misjudged when to let go.

He let go of that raft and drowned, unfortunately, that day.

- [Narrator] Eugene Williams' death lit up Chicago with white ethnic groups rampaging across the city for the better part of a week, looting and burning black neighborhoods.

In the middle of the violence were roving packs of Irish youths.

A group long oppressed had, as Farrell foretold, turned on a dime and joined the ranks of oppressor.

- Those who are oppressed oftentimes as they are looking to climb out of oppression, they will turn, unfortunately, their gaze onto the next targeted group.

- The racist behavior and violence directed at African-Americans cannot be excused, but in order to understand the dynamics of what occurred, you will have to look beneath the surface of the violence.

And at the core was being displaced from jobs and the perception that your community was also under attack as well.

And for them not to see that, the conditions were similar and to maybe pull their political power together to improve the conditions of both communities was unfortunate.

- [Narrator] In the riots aftermath, the Hamburg Athletic Association, a South Side Irish social club, was identified as one of the prime instigators of the violence.

One member of that club was a 17-year-old named Richard J. Daley.

Although there is no evidence he ever took part in the violence, Daley would later serve as president of the Hamburg Club.

(indistinct) That, of course, was only a harbinger of what was in store for Chicago as Richard J. would go on to become one of the most consequential politicians of the 20th century, and he would shape the city in his image, for better or worse.