Mary Maguire Alden was born in New York City on June 18, 1883. She appeared in her first film when she was 31 years old in the production of The Second Mrs. Roebuck (1914). From that point on, Mary was kept very busy in the studios in New York. When the film companies moved west, Mary went with them. She continued her torrid pace in filmmaking. Mary did make the switch from silent to sound movies, but she retired from work in 1935 after The Great Hotel Murder (1935). She died in Woodland Hills, California, on July 2, 1946.

Graduated from the American Academy of Dramatic Arts in New York City in 1910. Among her classmates were director Paul Bern (who was murdered by his first wife just after marrying Jean Harlow), and actors Tom Powers and George Shelton. William de Mille, whose father named the Academy when he was a teacher there, spoke at the graduation ceremonies for the Class of 1910. He and his brother Cecil B. also graduated from the Academy.