Mulligan was an American film and TV director. He studied radio communication at Fordham University and during WW II served in the marines as a radio operator. At the end of the war he got a job in the editing department of the New York Times, but soon abandoned this position because he wanted to start a career in television. He started at the bottom as a deliveryman at CBS but advanced quickly and by 1948 directed his first TV series. In 1957, he made his feature film debut with Fear Strikes Out. The film was produced by Alan J. Pakula with whom, in 1962, Mulligan founded the Pakula-Mulligan Productions Company. After his feature film debut, Mulligan continued directing TV series. In 1959 he made the TV film The Moon and Sixpence, which won an Emmy for Best Director. It starred Sir Laurence Olivier, in his first ever TV appearance and the role won him an Emmy as well. His next feature films were the romantic comedy The Rat Race (1960), The Great Impostor (1961) based upon a true story about a crook; comedy Come September (1961) and historical drama The Spiral Road (1962). His film To Kill a Mockingbird (1962) is his most famous film and it brought him recognition and an Oscar nomination for Best Film and Director, while Gregory Peck won an Oscar for Best actor. Afterwards he made Love With The Proper Stranger (1963) starring Natalie Wood and Steve McQueen, Baby the Rain Must Fall (1965) also starring Steve McQueen, Inside Daisy Clover (1965) with Natalie Wood and Robert Redford, Up The Down Staircase (1967) with Sandy Dennis and the western The Stalking Moon (1968), again starring Gregory Peck. In 1969, the production house Pakula-Mulligan Productions closed down and Alan J. Pakula began his own career as a director. After that Mulligan made the drama Pursuit of Happiness (1971), nostalgic drama Summer Of ’42 (1971), horror The Other (1972), crime film The Nickel Ride (1974), drama Bloodbrothers (1978), adaptation of a theatre play Same Time, Next Year (1978) starring Alan Alda and Ellen Burstyn and the comedy Kiss Me Goodbye (1982), actually a remake of the Brazilian film Dona Flor e Seus Dois Maridos (1976). His other films include Clara's Heart (1988) with Whoopi Goldberg and the romantic drama The Man in the Moon (1991), which was his last film.