This is what we found on Wikipedia regarding the Dee Diggs:

Ruby Dee (October 27, 1922 – June 11, 2014) was an American actress, poet, playwright, screenwriter, journalist, and civil rights activist. Dee was married to Ossie Davis, with whom she frequently performed until his death in 2005. She received numerous accolades, including two Emmy Awards, a Grammy Award, an Obie Award, and a Drama Desk Award, as well as a nomination for an Academy Award. She was honored with the National Medal of Arts in 1995, the Screen Actors Guild Life Achievement Award in 2000, and the Kennedy Center Honors in 2004.

Dee started her career with the American Negro Theatre. She made her Broadway debut in South Pacific (1943). She met her future husband working together on the play Jeb (1946). She originated the Broadway roles of Ruth Younger in Lorraine Hansberry's A Raisin in the Sun (1959) and reprised the role in the 1961 film and Lutiebell Gussie Mae Jenkins in the Ossie Davis play Purlie Victorious (1961) and reprised the role in the 1963 film.

She made her film debut in That Man of Mine (1946) before landing a leading roles in films such as The Jackie Robinson Story (1950), Edge of the City (1957), Take a Giant Step (1959), and Buck and the Preacher (1972). She also acted in the Ossie Davis film Black Girl (1972), and the Spike Lee films Do the Right Thing (1989) and Jungle Fever (1991). For her performance in American Gangster (2007), Dee was nominated for the Academy Award for Best Supporting Actress and won the Screen Actors Guild Award for Female Actor in a Supporting Role.

Dee received two Primetime Emmy Award nominations for her roles in The Doctors and the Nurses (1964) and Decoration Day (1990). She was nominated for her other roles in Roots: The Next Generations (1979), Lincoln (1988), China Beach (1990), and Evening Shade (1993). She also acted in I Know Why the Caged Bird Sings (1979), Long Day's Journey into Night (1982), Go Tell It on the Mountain (1985), The Court-Martial of Jackie Robinson (1990), and The Stand (1994). She voiced Alice the Great in the Nick Jr. series Little Bill from 1999 to 2004.