- Motley was the first African-American woman to argue a case before the U.S. Supreme Court, which she did in 1946.
- She was also the first African-American woman to serve as a federal judge, when she was appointed to the U.S. District Court for the Southern District of New York in 1961.
- Motley was a key figure in the civil rights movement, and her legal work helped to dismantle segregation and discrimination in the United States.
- She was also an active member of the National Association for the Advancement of Colored People (NAACP), and served as the organization's general counsel from 1961 to 1980.
- Motley received numerous awards and honors for her work, including the Presidential Medal of Freedom in 1968 and the NAACP Spingarn Medal in 1964.
- She was also inducted into the National Women's Hall of Fame in 1993.