11/17/2008 at 01:00 AM EST
ERIQ LA SALLE
premiered Sept. 19, 1994—in a time slot opposite another hospital drama, Chicago Hope
—not even the show's creators were optimistic about their prognosis. "I think we all thought we would be done by Christmas!" says executive producer John Wells. At its peak, 32 million viewers returned each Thursday to watch the cast of relative unknowns—including Anthony Edwards, Julianna Margulies and some guy named George Clooney
. The years rolled on and original cast members left to pursue other goals, but the show remained a hit.
Says Wells: "It was wonderful and shocking to have it last this long." As ER embarks on its 15th and final season (the doctors will treat their last patient next spring), "there hasn't been a moment to stop and consider," says Wells. "It will be a very unusual day for me when it's all over."