Vondie Curtis-Hall appeared on the show as two characters. In season one he played a transsexual (for which he was nominated for an Emmy) and in later episodes played Carla's husband and fought Dr. Benton for custody of his son, Reese.
Carol Hathaway (Julianna Margulies) was supposed to be brain-dead from a suicide attempt in the first episode, but the character was revived for the series. For the first episode, Margulies was credited as a guest star.
If anything had gone wrong during the broadcast of the live episode, such as a technical failure or forgotten dialogue, the producers had additional actors ready to improvise a scene that would have been inserted to cover. This contingency was never used.
Dr. Romano (Paul McCrane) has a model of an Apollo Saturn V rocket in the background of his office. McCrane played astronaut Charles Conrad, commander of Apollo 12, in the HBO mini-series _"From the Earth to the Moon" (1998) (mini)_
The character played by Ming-Na Wen was addressed only as Deborah Chen when she first appeared in the series in 1995. When she returned in 2000, she took to a more traditional name, Jing-Mei, which was also the name of the character Ming-Na played in The Joy Luck Club (1993).
George Clooney's cousin, Miguel Ferrer, appeared as a guest star in the two-hour pilot episode, and Clooney's aunt, Rosemary Clooney (Ferrer's mother), appeared in the second regular episode. Clooney shared scenes with neither of them.
Frank, the desk clerk (Troy Evans), always talks about life on the "force" as a Chicago police officer. In a very early episode he had an appearance as a police officer who was shot and treated by the ER staff.
In one episode, Dr. Lewis admits that she's only familiar with the Walt Whitman poem "I Sing the Body Electric" because it appeared in song form in the movie Fame (1980). That song in that film was sung by Paul McCrane (Dr. Romano).
The character of Dr. John Carter was named after the protagonist in the classic "John Carter: Man from Mars" pulp sci-fi stories. Michael Crichton, like many sci-fi writers, considers it an early influence.
The basketball hoop found outside the ambulance bay of the ER was actually George Clooney's idea. Apparently the actor likes to unwind in between takes by shooting some hoops. Because this, it was placed in an area of the Warner Brothers (Burbank, California) studio lot where it could be picked up by the camera. It quickly became a part of the series itself.
The character portrayed by Leslie Bibb, Erin Harkins, was originally supposed to die in the episode where she and Luka (Goran Visnjic) were in a car accident. The producers changed their mind after the episode had been written, and after an ambiguous ending, she resurfaced a couple of episodes later, alive and well.
Noah Wyle was the last member of the original cast to leave, at the end of the 2004-2005 season. He will appear occasionally in future seasons. Sherry Stringfield is also an original cast member, but she left for 5 seasons, which made Noah Wyle the only cast member to be on the show every year for the series first eleven seasons.
Including Gloria Reuben and CCH Pounder (who appeared as recurring guest stars during the first season), the original cast combined for 25 nominations in the Leading and Supporting Acting categories at the Emmy Awards from 1995-2000. Julianna Margulies (Best Supporting Actress, 1995) was the only one to ever win.
The first four episodes of the show all began the same way, with one of the doctors being awakened early in the morning from "Exam 8" at the end of the hallway in this order: Greene (Pilot), Lewis (Day One), Benton (Going Home), Carter (Hit and Run). This became a recurring motif throughout the run of the series, and the 200th episode began this way as well. Of the original five doctors, Ross (George Clooney) was the only one who was never shown sleeping in Exam 8.
Doug Ross frequently hung his head low, appearing ashamed or thoughtful or privately amused, depending on the scene. This wasn't just an element of the character: George Clooney had taken to writing his lines on papers, sheets, and other props (especially that complicated medical terminology).
The set for the pilot episode was a rundown hospital in East Los Angeles, as they couldn't afford to build a proper set of their own. As the rooms were quite small, this necessitated the use of the Steadicam, which has since become the trademark of the show. Real members of the public, usually Punk gangs, would often pull up outside, mistaking the set for the real thing.
Although mostly shot at Warner Brother's Burbank soundstages, the cast and crew usually will make at least two trips to Chicago each season to shoot realistic exterior scenes for several episodes which include many familiar Chicago landmarks. These scenes are normally shot on early Sunday mornings to avoid disrupting traffic.
Producers wanted the character of Carol, played by Julianna Margulies to switch from being a nurse to a doctor and even filmed episodes of her starting medical school. Margulies objected to the idea, saying that her character would be so proud of being a nurse she would never want to change, so the idea was dropped. Years later, the character of Abby, played by Maura Tierney did go from being a nurse to a doctor.
Gloria Reuben (Jeannie Boulet), and Erik Palladino (Dave Malucci) left the show because they felt that their characters were being under-used. Kellie Martin (Lucy Knight) left the series when it became too painful to work in a medical show following the death of her sister.
Some of the operations in the series were dramatized versions of real-life operations. The writers scouted out hospitals around the L.A. area to get ideas for new episodes. An early episode, in which a baby gets a coat hanger stuck in it's throat, was based off a real emergency in a Los Angeles hospital. However, the situation was dramatized by adding a scene where the baby bleeds profusely, and requires a tracheotomy (in real life, they simply reached in and pulled the hanger out).
Glenne Headly was pregnant when she signed on to do her story arc as Dr Abby Keaton in the third season. Originally the writers floated the idea of writing the pregnancy into the show but then decided that audiences would have difficulty accepting John Carter having a relationship with a heavily pregnant woman. In the later stages, Headly had to be photographed behind gurneys and in ill-fitting surgical scrubs to hide her bump.
Originally planned as a film, which Steven Spielberg was supposed to direct. When plans fell through and the project eventually became a series, Spielberg became interested in another Michael Crichton creation: Jurassic Park (1993).
Casting director John Frank Levey originally suggested Michael Beach for the role of Dr. Peter Benton. John Wells felt Beach didn't complete the ensemble and chose Eriq La Salle instead. Beach eventually appeared on ER as Al Boulet. Beach would also later be cast as a regular Third Watch (1999), another Wells-produced series.
Anthony Edwards was first choice to play the part of Dr Mark Greene. Unfortunately Edwards was committed to direct a feature film at the time the pilot was due to shoot and was therefore unavailable. By sheer luck, his feature was pushed back and he was able to film the pilot instead.
Because the show could make only a couple of location shoots in Chicago each year, the exterior scenes would often have to be filmed in advance of the rest of the episode's shoot back in LA. Sometimes a scene for an episode would have to be shot before it was even written. A famous example of this is the final scene in "Love's Labor Lost," when Dr. Greene cries on the EL. Director Mimi Leder could only give Anthony Edwards a brief description of what was to occur and told him to "find it," "it" being the sadness Greene was experiencing.
Troy Evans, who would later play desk clerk Frank Martin appeared in the pilot as a character referred to as Officer Martin. In scripts, the first name was Jonathan. There was never any indication given in the show if this is the same character and as of the series finale, producers would not speculate either.
Due to a lack of time and money to build a set, the pilot episode of ER was filmed in the former Linda Vista Community Hospital in Los Angeles, an old facility that ceased operating as a medical center in 1990.
Season 14 was supposed to be the final season but the 2007-08 WGA strike left both the producers and NBC without enough episodes to provide a proper final victory lap season. They agreed to bring the show back for the 15th and last season, that began in September 2008 and concluded on April 2, 2009.
The first six DVD box sets of ER are unusual in the fact that they are all in anamorphic widescreen even though these episodes were broadcast in a standard 4:3 format. Only the live episode "Ambush" is not in the widescreen format.
All original cast members who appeared in Season 15 were listed in the credits with the current stars, not as guest appearances. Alex Kingston and Laura Innes also appeared in the opening credits to the series finale due to their roles in it. In the 2009 episode guest starring George Clooney and Julianna Margulies, Noah Wyle received top billing over both of them.
Because the original credits were abandoned in season 13, neither Maura Tierney or Parminder Nagra were seen with the "Starring" moniker attached to their name, although they were each the lead roles for a time. John Stamos, Angela Bassett, and David Lyons were depicted in the opening credits just once, when the original style was brought back for the series finale
Laura Innes and Noah Wyle tied as the series' longest-appearing cast members, having appeared in 13 out of 15 seasons. Innes' Dr. Kerry Weaver made her first appearance in Season 2, stayed on as a regular until the midpoint of Season 13, and appeared in two Season 15 episodes. Wyle's Dr. John Carter was a regular from the start of Season 1, left the regular cast in the Season 11 finale, had a multi-episode guest role in Season 12 (for a story set in Darfur), and returned for several Season 15 episodes. Both actors were in the series finale and had a few scenes together.
Miguel Ferrer and Michael Ironside have both appeared on this show. Their names are actually quite similar. Miguel is, of course, the Spanish form of Michael. Ferrer is derived from Ferrum, the Latin word for Iron, and Ferriere, a French iron-mining town.