Blackman made her television-acting debut as a guest performer in a 1957 series, Hawkeye and the Last of the Mohicans.
Among her television appearances was her role as Hilary Gray in the 1964 Perry Mason episode "The Case of the Ruinous Road." She played opposite Jack Lemmon in the episode "Disappearance" of Alcoa Theatre in 1958 and also made single appearances on Bonanza, I Spy, and Gunsmoke.
During the 1965–1966 season, Blackman was part of the regular cast of the primetime television serial Peyton Place. On that show, she played Marion Fowler, the wife to the district attorney.
Personal life
In May 1959, Blackman married Joby Baker, a fellow actor she met in drama school. The couple divorced two years later, in November 1961. She then married actor Rockne Tarkington in July 1968. They had two children before divorcing in October 1970.[citation needed]