Final answer:
D.W. Griffith was considered racist due to his film 'The Birth of a Nation,' which promoted white supremacist views and portrayed African Americans negatively, leading to increased racial tensions and the resurgence of the KKK.
Step-by-step explanation:
D.W. Griffith, the filmmaker, was considered racist chiefly due to his film The Birth of a Nation, which depicted the Ku Klux Klan in a heroic light and portrayed African Americans using harmful stereotypes and historical inaccuracies. The film's narrative supports a racist view of the Reconstruction Era, suggesting noble White southerners were victimized by northern carpetbaggers and newly freed African Americans. The negative portrayal of Black characters as unintelligent and dangerously unrestrained towards White women exacerbated racial tensions and validated the white supremacist narrative of the time. African American historians and activists from the NAACP actively countered the film's portrayal and worked to challenge its historical revisionism and racist implications. Notably, the film's release is associated with the resurgence of the Ku Klux Klan in the 20th century.