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
Acclaim Studios Austin of America, but getting to know Texas' expanding technology industry, several Iguana staff traveled to Austin in May 1993 to investigate the relocation possibilities in the area. The team returned with videotape of the city's Sixth Street entertainment district. All but one employee agreed to move to Austin, and the relocation was completed shortly after. Later that year, Iguana achieved its first success with "Aero the Acro-Bat" and used profits generated from the game's sales to acquire Stockton-on-Tees-based developer Optimus Software, which was rebranded Iguana UK. On December 21, 1994, Acclaim announced that they had agreed into acquiring Iguana. The