On August 21, 1955, fourteen-year-old Emmett Till arrived in Money, Mississippi to visit his uncle and his cousins.  Four days later, the boys would take a drive to a grocery store owned by a white couple, Roy and Carolyn Bryant.  To this day, the interaction between Till and Carolyn Bryant is disputed, but it's said that Till, a Chicago native unaccustomed to the deep South, allegedly whistled at Bryant.  This would spur the events of August 28th, when Roy Bryant and his accomplices arrived at the home of Till's uncle, forced Till into their vehicle, and drove him to a barn in the town of Drew.  There, they committed the horrific crime that months later would inspire a brave woman on a  Montgomery bus to take a stand - by sitting down -  and a movement to the "solid rock of brotherhood" that would resonate for decades to come.

Main Source:

Tell, Dave.  Remembering Emmett Till.  University of Chicago Press, 2019.