A major director during the silent era, his career in the sound era was very adversely affected due to a serious drinking problem.
Child with Bambrick: Marshall Ambrose (25 May 1915)
Father of screenwriter Marshall Neilan Jr.
His association with Mary Pickford is discussed in Scott Eyman's book "Mary Pickford: America's Sweetheart", (1990).
In 1912 Neilan was working as a car salesman at a dealership in La Mesa, California, when he was instructed to deliver a car to a nearby film location, whose director had just purchased it. Neilan delivered the car to the director, Allan Dwan, and since Dwan didn't know how to drive, Neilan took him out and taught him. The two hit it off and Dwan asked Neilan if he wanted to be an actor in his film. When Neilan discovered that the job would pay twice as much as his car salesman job, he took it, beginning his long career as an actor, writer and director.