Born Jack Dudley Jenkins in Los Angeles, the son of actress Doris Dudley, Jenkins made his film debut at the age of six in The Human Comedy (1943) as "Ulysses Macauley" after an MGM talent scout saw him playing on a Santa Monica beach and admired his high spirits.

[1] His performance as Mickey Rooney's younger brother (The Human Comedy) was well received and Jenkins was cast in a succession of films.

He was described by film writers Sol Chaneles and Albert Wolsky as "an audience favourite as an all-American boy [with a] space between his teeth, freckles and a tousled mop of hair – a marked contrast to the pretty children who usually appeared on screen.

[3] Jenkins retired from acting at the age of eleven, after he developed a stutter,[4] and as an adult recalled his film career fondly and without regret.

[citation needed] Later described as a "businessman-outdoorsman", Jenkins established a successful career away from Hollywood and lived for many years in Dallas, Texas, before moving to North Carolina in the late 1970s,[5] where he built a home "on the side of a steep mountain", where he resided with his third wife, Gloria.