The Tulsa Race Massacre beats it by a few months, May 31st to June 1st. It leveled around 35 blocks of a wealthy black community, partly using firebombs dropped from planes, which was known up until that point as "Black Wall Street". A 2001 commission put the death count somewhere between 150-300 deaths, and noted that the city aided in the massacre.
The Tulsa Race Massacre beats it by a few months, May 31st to June 1st. It leveled around 35 blocks of a wealthy black community, partly using firebombs dropped from planes, which was known up until that point as "Black Wall Street". A 2001 commission put the death count somewhere between 150-300 deaths, and noted that the city aided in the massacre.
Wikipedia
It's also very accurately and devastatingly depicted in HBO's "Watchmen"
Side note: Greenwood was planned by Booker T Washington. There are actually several Greenwood districts throughout the south.