She was born Mary L. Mulhern on January 24, 1908 in Newark, New Jersey. When she was a child her family moved to Manhattan where her father worked as a salesman. At the age of seventeen Mary started dancing in the chorus of the Ziegfeld Follies. Then Florenz Ziegfeld cast her in his the 1926 Broadway show No Foolin. The beautiful brunette appeared in several Vitaphone shorts including Just Like A Man and Somewhere In Jersey. She fell in love with entertainer Harry Richman but he left her for Clara Bow. On August 12, 1930 she married actor Jack Pickford. He was the brother of movie star Mary Pickford and the widow of Olive Thomas. Unfortunately Jack was an alcoholic and often became abusive. When he was injured in a car accident in 1931 she was forced to be his full-time nurse.
Mary divorced him in February of 1932 claiming he was "a jealous man who sleeps until 4 in the afternoon". Soon after Jack Pickford died from neuritis. In 1936 she married Edward McCarty, a twenty-eight year old stockbroker. Tragically he died just four years later. She married her third husband in 1941 but they divorced a few years later. Mary also dated prize fighter Jack Dempsey and was briefly engaged to a British nobleman. As she got older she struggled with money and depression. She worked at several low paying jobs including being the hostess at an ice-cream shop. Then in May of 1955 she was committed to a mental hospital in New York. Sadly she would remain institutionalized for the rest of her life. On October 25, 1965 she died at the age of fifty-seven. She was buried at Kensico Cemetery in Vahlalla, New York. Her grave was paid for by the actors fund.
