Before becoming widely known for his role as Mark McCain on the long-running western series The Rifleman, he freelanced for two plus years, accumulating over 60 TV credits. His final film appearance was in the 2019 movie The Marshal. He played the character William S. Hart.
He began his career as an original Mouseketeer at age nine.
He was nominated for a 1959 Primetime Emmy for his role in The Rifleman. He was featured on the soundtrack of the popular 2004 action movie Hellboy.
He married Charlotte Crawford in 1995.
He acted with John Wayne in the 1966 western El Dorado.