Known best for his role as John-Boy on TV's The Waltons, he began his television career in 1959 in a version of A Doll's House before moving on to appear in some soap operas.
He majored in Chinese at Columbia University and speaks the language fluently.
He starred in The Waltons with Michael Learned.
He made his Broadway debut at age seven with the assistance of his parents, who were both ballet dancers.
He married Alma Gonzales in 1975 and the couple welcomed triplets in 1981.
- The meaning of the name Thomas: A Twin