Petersen started out in show business at the age of ten when he became a "Mouseketeer" on the Mickey Mouse Club. He was fired within two weeks for disorderly conduct. He was later quoted as saying, "I didn't know a kid actor shouldn't act like a kid." However, he achieved stardom as a teenage heartthrob on The Donna Reed Show, an ABC family sitcom that ran from 1958 to 1966. He played son Jeff Stone from the time he was twelve until he was twenty. In addition, he learned a great deal from Reed while he was growing up on the television set. Above all, he realized that Donna was his favorite actress to date in his business. Petersen sang his sentimental hit song My Dad to costar Carl Betz, who portrayed Dr. Alex Stone, in a 1962 episode of the series. His other costars were Shelley Fabares and his real-life sister Patty Petersen as well as the late Bob Crane.
Afterwards he was in many guest-roles, but fewer and fewer as the years passed. He said that too many casting directors do not permit Bubblegum stars to grow into adult actors. Hence, his Jeff Stone character was particularly typecasted.
Petersen's fame brought recording offers and although his singing voice was limited, he had hit record singles with songs "She Can't Find Her Keys", "Amy", and "Lollipops and Roses", as well as "My Dad" that made the Billboard Hot 100. He also recorded during the 1960s for Motown, including the singles "Chained" (later a hit for Marvin Gaye) and "A Little Bit For Sandy."
Difficult times followed his almost instantaneous disappearance from the Hollywood spotlight. As a result, Petersen returned to the university and obtained a degree in literature that helped him to write sixteen adventure novels.
Petersen's authorship began after he met David Oliphant, a New York publisher visiting Los Angeles. His first novel concerned car racing. Thereafter, he created a Matt Helm-type hero, Eric Saveman, also known as "The Smuggler." In one year, Pocket Books published eight of his Smuggler novels, earning Petersen $75,000.
Petersen has been married 3 times: In 1967, Peterson married actress Brenda Benet. When she was having an affair with Bill Bixby, the couple divorced in 1970. In 1974, Peterson married Hallie Littman; they had two children, then were divorced in 1988. Peterson married Rana Jo Platz in 1992.
In 1990, he founded the child-actor support group called A Minor Consideration to improve working conditions for child actors and to assist in the transition between working as a child actor and adult life, whether in acting or in other professions.
He is currently the board member of the Donna Reed Foundation, and works for the Donna Reed Festival, which takes place on the third week of June, every year, in his mentor's hometown of Denison, Iowa.
