Final answer:
Lillian Smith was active in the National Association for the Advancement of Colored People (NAACP), which led the fight against racial violence and lynching.
Step-by-step explanation:
Lillian Smith was active in the National Association for the Advancement of Colored People (NAACP), an organization that played a critical role in the fight against racial violence and lynching in the United States. The NAACP was a key group in advocating for civil rights, including promoting anti-lynching legislation.
The NAACP's vigilant campaign to end lynching led to increased awareness of racial violence directed against African-Americans and was part of a broader New Negro movement that sought racial pride, cultural self-expression, economic independence, and progressive politics. By contrast, the Ku Klux Klan was a White supremacist group known for its anti-Black violence and intimidation, while the Black Panthers and Southern Christian Leadership Conference (SCLC) were involved in the civil rights movement at different times and in different capacities than the NAACP's specific anti-lynching efforts during Lillian Smith's era.