Cast of ER Cast of ER "ER" is an American drama series that aired on NBC from September 19, 1994 until April 2, 2009. The series featured a large ensemble cast that changed dramatically over its long run. The main cast was augmented by a wealth of recurring characters and award-winning guest stars. The original starring cast consisted of Anthony Edwards as Dr. Mark Greene, George Clooney as Dr. Douglas "Doug" Ross, Sherry Stringfield as Dr. Susan Lewis, Noah Wyle as medical student (later Dr.) John Carter, and Eriq La Salle as Dr. Peter Benton. Julianna Margulies guest starred in the pilot as
Andrew Walker (actor) Award nominee David Strathairn, playing a Neo-Nazi skinhead in the film "Steel Toes". His performance won him a 2006 Phillip Borsos award at the Whistler Film Festival and the 2008 ACTRA Award for Best Actor. Walker appeared in the 2007 Lifetime film "Abducted: Fugitive for Love" portraying the charismatic Jack Carlson, which was a huge hit among the female demographic. Subsequently, Walker acquired a large fan base. He went on to guest star on "ER", "", "", "Without a Trace" and "The Big Bang Theory". In 2010, he guest-starred in the Fox comedy series "Sons of Tucson", the spaghetti western