Due to his parents' involvement in community theater productions, Hamer and his brothers performed in stage productions. As a toddler, Hamer memorized and recited stories and performed skits for service club luncheons, women's clubs, and church groups. In 1951, the Hamers moved to
Los Angeles, where Arthur Hamer worked as representative for a manufacturer of men's sport shirts. Arthur Hamer died eight months after his son was cast in
The Danny Thomas Show). Shortly after arriving in Los Angeles, Hamer's older brother John was discovered by an agent while performing in a local stage production in which Rusty was also performing. The agent signed both boys to a film contract. In 1953, entertainer
Danny Thomas's secretary saw Hamer in a stage production and was impressed by the child's talent and charm. She suggested that Thomas audition Hamer for a role in his upcoming sitcom
Make Room for Daddy. Thomas was also impressed by the 6-year old and cast Hamer as his precocious and quick-witted son, Rusty Williams.
Make Room for Daddy debuted on
ABC on September 29, 1953, and, while critically acclaimed, garnered poor ratings. After four seasons, the series moved to
CBS where it was re-tooled and retitled
The Danny Thomas Show. During the run of
The Danny Thomas Show, Hamer attempted to launch a singing career. He first performed a song in a 1956 episode of
Danny Thomas entitled "The Talented Kid". In 1959, Hamer released his only single, a "rockaballad" called "Two-of-a-Kind" (with the
b side "If Only Mother Would Let Me") written by
Wally Gold and
Aaron Schroeder, through
Mercury Records. The single was a commercial failure and Hamer never released another single. By late 1963,
The Danny Thomas Show had garnered five
Primetime Emmy Awards (among other awards) and was still ranked in the Top 10. However, Danny Thomas announced that he had decided to end the show in order to produce and star in other projects. After the series ended, 17-year-old Hamer enrolled at Palisades High School (later restructured as
Palisades Charter High School), but had difficulty adjusting to public school as he was accustomed to being privately tutored on the set. On December 27, 1966, Hamer underwent emergency surgery at Santa Monica Emergency Hospital after sustaining a gunshot wound to the abdomen when a gun he was carrying in a shoulder holster slid out, fell to the ground, and discharged. Hamer was carrying the gun having just returned from an overnight hunting trip. After recovering, he appeared in a second reunion special, "Make More Room For Daddy", that aired during a segment of the NBC
anthology series The Danny Thomas Hour, in 1967. To support himself, he began working for a messenger service in Los Angeles and later worked as a carpenter's apprentice. ''. In 1969, Hamer again reprised his role as Rusty Williams in a third reunion special,
Make Room for Granddaddy. The special aired on CBS on September 14. Due to the ratings success of the reunion specials, ABC created a weekly sequel series, also titled
Make Room for Granddaddy, for their fall 1970 schedule. The series premiered on September 24, 1970, but failed to catch on with audiences.
Make Room for Granddaddy was cancelled after one season. It was Hamer's final acting role. ==Later years==