Answer:
It was a breaking point for this sort of thing
Step-by-step explanation:
Im going to compare this to the BLM movements, George Floyd was not the first Black person to be murdered by police brutality, but all the previous cases built up to this case and it was the breaking point. It's the same thing for this, Emmett Till was not the first but his case was the breaking point for stuff like that.
Hopefully this helps!