Born Sophie Kosow, Sidney was an intense, vulnerable, waif-like leading lady with a heart-shaped face, trembling lips, and sad eyes. The daughter of Jewish immigrants from Russia, she made her professional acting debut at age 16 in Washington after training at the Theater Guild School. The following year she made her first New York appearance and quickly began to land lead roles on Broadway. She debuted onscreen as a witness in a courtroom drama, Through Different Eyes (1929). In 1931 she was signed by Paramount and moved to Hollywood. In almost all of her roles she was typecast as a downtrodden, poor but proud girl of the lower classes -- a Depression-era heroine. Although she occasionally got parts that didn't conform to this type, her casting was so consistent that she had tired of film work by the late '40s and began devoting herself increasingly to the stage; she has since done a great deal of theater work, mostly in stock and on the road. After three more screen roles in the '50s, Sidney retired from the screen altogether; seventeen years later she made one more film, Summer Wishes, Winter Dreams (1973), for which she received a Best Supporting Actress Oscar nomination, the first Oscar nomination of her career. In 1985 she portrayed a dying woman in the TV movie Finnigan, Begin Again. Her first husband was publisher Bennett Cerf and her second was actor Luther Adler.