Tulsa, Oklahoma has a long history of land seizing, racial tension and slavery, amongst being one of the most beautiful cities in the United States now. In the 1830s, the area was Indian Territory, and after the Civil War a small section of the town was dedicated to the black community of freed citizens, as the white citizens of Tulsa put up many rules to keep the more affluent areas of the city, segregated.
Even when the town boomed, thanks to oil, and other affluent black men arrived in the area, they too were restricted to Greenwood. So they took their wealth and invested it into the small black-own businesses operating with the small area of the town they were allowed to have, and soon the community of Greenwood flourished with all individuals gaining individual wealth.
Until Memorial Day in 1921, when a small interaction that is almost not even worth nothing, led to a white mob completely destroying Greenwood, without a single consequence.