Biography
Pernell Elvin Roberts, Jr. (May 18, 1928 – January 24, 2010) was an American stage, movie and television actor as well as singer. In addition to guest starring in over 60 television series, he was widely known for his roles as Ben Cartwright's eldest son, Adam Cartwright, on the western series Bonanza, a role he played from 1959 to 1965 — and as chief surgeon Dr. John McIntyre, the title character on Trapper John, M.D. (1979–1986).
He was also widely known for his life-long activism, which included participation in the Selma to Montgomery marches in 1965 and pressuring NBC to refrain from hiring whites to portray minority characters.
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Filmography
Cast Credits

Diagnosis: Murder
Character: Dr. Elliott Valin
TV • 1993

Diagnosis: Murder
Character: George Fallon
TV • 1993
FBI: The Untold Stories
Character:
TV • 1991

Donor
Character: Dr. Simon Martingale
MOVIE • 1990

Checkered Flag
Character: Andrew Valiant
MOVIE • 1990

Perry Mason: The Case of the All-Star Assassin
Character: Thatcher Horton
MOVIE • 1989

Around the World in 80 Days
Character: Captain Speedy
TV • 1989

The Night Train to Kathmandu
Character: Prof. Harry Hadley-Smithe
MOVIE • 1988

Desperado
Character: Marshal Dancey
MOVIE • 1987

Realm of the Alligator
Character: Narrator
MOVIE • 1986

Night of 100 Stars II
Character: Self
MOVIE • 1985

Hotel
Character:
TV • 1982

Night of 100 Stars
Character: Self
MOVIE • 1982

Incident at Crestridge
Character: Mayor Hill
MOVIE • 1981

High Noon, Part II: The Return of Will Kane
Character: Marshal J.D. Ward
MOVIE • 1980

Trapper John, M.D.
Character: "Trapper" John McIntyre
TV • 1979

Hot Rod
Character: Sheriff Marsden
MOVIE • 1979

The Night Rider
Character: Alex Sheridan
MOVIE • 1979

The Immigrants
Character: Anthony Cassala
MOVIE • 1978

Centennial
Character: General Asher
TV • 1978