American actor, James Arness, (brother of Peter Graves) is best known for portraying Marshal Matt Dillon on Gunsmoke for 20 years. Arness has the distinction of having played the role of Marshal Matt Dillon in five separate decades from 1955 to 1975 in the weekly series.
James Arness - ALIVE
James Arness was primarily identified with Westerns, although he is also known for appearing in two science fiction films, "The Thing from Another World" (in which he portrayed the title character) and "Them!". He was a close friend of John Wayne and co-starred with him in "Big Jim McLain", "Hondo", "Island in the Sky" and "The Sea Chase".
After Gunsmoke ended, Arness performed primarily in westerns and western-themed TV series, including "How the West Was Won", and five made-for-television "Gunsmoke" reunion movies between 1987 and 1994. A notable exception was a brief turn as a big city police officer in the short-lived 1981 series, "McClain's Law".
Peter Graves - DEAD
James Arness Is still alive and kicking as of the time of this writing. But his brother Peter Graves (He changed his name from Arness to Graves.) who starred in the long running TV show "Mission Impossible" and the comic movie "Airplane" did die today March 15, 2010. Beware the Ides of March Peter!