There were several events in the 1920s that marked a rise in racial tensions in the United States. One major event was the resurgence of the Ku Klux Klan, a white supremacist organization that had been dormant since the late 19th century. The KKK experienced a resurgence in the 1920s, fueled by a wave of nativism and anti-immigrant sentiment, and it began targeting not only African Americans but also Jews, Catholics, and other groups seen as a threat to white Protestant dominance.
Another event that contributed to racial tensions in the 1920s was the Great Migration, in which millions of African Americans moved from the rural South to cities in the North and West in search of better economic opportunities. This migration led to increased competition for jobs and housing, and it sparked tensions between African American migrants and white residents in many cities.
Additionally, there were a number of race riots in the 1920s, including the Tulsa Race Massacre in 1921, in which a white mob attacked and destroyed a thriving African American community in Tulsa, Oklahoma, resulting in the deaths of hundreds of people.
Overall, the resurgence of the KKK, the Great Migration, and race riots were all indicators of rising racial tensions in the 1920s.