scattered sites primarily in "Black Valley" between 4th and 6th Street and Broadway to Railroad Avenue

In July 1917, East St. Louis was the scene of one of the bloodiest race riots in American history. Tensions in the community had been increasing throughout the spring of 1917. The city's Black population had rapidly increased between 1910 and 1917, and white workers at local stockyards, packing plants, and factories resented the influx of cheap new labor. In April, Aluminum Ore Corporation, one of the city's largest plants, went on strike, and some of the strikebreakers were Black. After management crushed the strike, white workers blamed the Black workers for their defeat.

In May, rioting broke out briefly, culminating in a meeting where white labor workers appeared before the city council to protest the Black migration. On the evening of July 1st, some whites in a speeding car shot randomly into homes in a Black neighborhood. When detectives arrived to investigate, a crowd of Black residents, apparently mistaking the detectives for more drive-by murderers, fired on their car, killing one detective and fatally injuring the other.

On July 2nd, 1917, riots erupted. White mobs pulled innocent Black citizens off streetcars and murdered residents as they tried to escape the flames. By evening, most remaining Black residents had fled the city or were escorted to safety by arriving state militiamen. Thirty-nine Blacks and nine whites died in the rioting, and 312 buildings were destroyed as a result. A large portion of the Black population left East St. Louis, many never to return.

The National Committee investigated the incident and filed a scathing report condemning corrupt East St. Louis politicians, as well as local industrialists who exploited Black workers. Eleven Blacks were convicted of murdering the detectives, but only four whites went to prison for murder.