Claim: James Arness acted.

James Arness -LRB- May 26 , 1923 -- June 3 , 2011 -RRB- was an American actor , best known for portraying Marshal Matt Dillon for 20 years in the television series Gunsmoke . Arness has the distinction of having played the role of Dillon in five separate decades : 1955 to 1975 in the weekly series , then in Gunsmoke : Return to Dodge -LRB- 1987 -RRB- and four more made-for-television Gunsmoke films in the 1990s . In Europe , Arness reached cult status for his role as Zeb Macahan in the western series How the West Was Won . He was the older brother of actor Peter Graves -LRB- 1926 - 2010 -RRB- .