From Wikipedia, the free encyclopedia. Aline MacMahon (May 3, 1899 – October 12, 1991) was an American actress. MacMahons career began in theatre during the 1920s, and she worked extensively in film and television, until her retirement in the mid 1970s. She was nominated for an Academy Award for Best Supporting Actress for her performance in Dragon Seed (1944). Description above from the Wikipedia article Aline MacMahon, licensed under CC-BY-SA, full list of contributors on Wikipedia.