On July 27, 1919, a teen-aged black swimmer breached the unholy, unofficial color line at 29th Street Beach and invaded “white” Lake Michigan waters.

Eugene Williams was pelted with stones tossed by whites and drowned. Police refused to arrest the white man identified as the instigator.

This set off eight days of battling between white and black gangs in the South Side’s Back of the Yards and Bridgeport area that left 23 blacks and 15 whites dead, plus 500 injured. Another 1,000 African Americans were left homeless after white marauders torched their homes.

Opinion

One of two Bridgeport Irish gangs joining the riot was the Hamburg Athletic Club. One of the Hamburgers was 17-year-old Richard J. Daley, who would become the most powerful and racially divisive mayor in city history. Whether he actually fought in the riots remains an unanswered question obscured by official denials.

Since then, up to this very day, racism and its unholy companion, xenophobia, have been defining elements in Chicago’s culture.

There would be more “race riots,” with whites attacking blacks for being in the “wrong” place: Airport Homes in 1946, Trumbull Park in 1955, and Marquette Park in 1965, where Dr. Martin Luther King Jr. was struck by a brick.

And there would be dozens of other incidents, such as a black family being burned out of a Bridgeport home and African Americans burning the West Side in the wake of King’s murder.

Chicago’s African American population of 100,000 in 1919 grew to more than 1 million by 1980, and the city became the most racially segregated in the Western world. The pattern was not originated by Daley, but he used every instrumentality of his government to generate and perpetuate this segregation. He gave Chicago the largest area of 90-plus percent black residents anywhere outside of Africa.

By the end of Daley’s 22 years in office, his patronage system, school system, housing authority, park district and police and fire departments had been found guilty of constitutional or civil rights violations. His electoral board had been found guilty of racial gerrymandering, even as his planners had drawn street lines and expressway paths designed to head off or stop black migration.

Chicago’s entire criminal justice system even now remains unfair to blacks and Latinx.

Chicago continues to suffer from segregation’s ills, even as we make political and social progress. Out of our segregated snakepit emerged independent social and political movements to fight racism in the courts, on the streets and at the ballot box.

We elected a black mayor, Harold Washington, in 1983, though he was stymied by a hostile white majority in the City Council led by an alderman from the Trumbull Park ward.

We have sent three African Americans to the U.S. Senate — and one became president.

But after Washington died, another son of Bridgeport created an illegal Hispanic patronage organization to generate hostilities between blacks and Latinx. He oversaw the depopulation of 200,000 African American residents by tearing down massive housing projects without providing alternate affordable housing.

Intentional? In Chicago? Perish the thought.

Today, African American women run the city and the county. We’ve come a long way from 1919, baby — but we’ve got a long way to go.

Don Rose, the veteran political consultant, writes a column for the Chicago Daily Observer.

Send letters to: letters@suntimes.com.