Final answer:
The Tulsa Race Massacre has been downplayed in mainstream narratives of American History up to the present due to systemic racism and intentional suppression.
Step-by-step explanation:
The Tulsa Race Massacre has been downplayed in mainstream narratives of American History up to the present due to systemic racism and intentional suppression. This tragic event, which took place in 1921, resulted in the deaths of hundreds of Black residents and the destruction of the prosperous Greenwood District in Tulsa, Oklahoma. The accounts of the massacre were often omitted from historical records, textbooks, and media for many years, reflecting a deliberate attempt to erase this dark chapter of American history.