History Trivia / ER

*** HilariousInHindsight now that Creator/DickWolf has created the ''Series/OneChicago'' franchise that includes its own ''Series/{{ER}}''-esque show, ''Series/ChicagoMed.'' Although perhaps doubly so, since every show in the franchise has had a cross-over with ''Series/LawAndOrderSpecialVictimsUnit'' '''except''' ''Chicago Med.''

*** HilariousInHindsight now that Creator/DickWolf has created the ''Series/OneChicago'' franchise that includes its own ''Series/{{ER}''-esque show, ''Series/ChicagoMed.'' Although perhaps doubly so, since every show in the franchise has had a cross-over with ''Series/LawAndOrderSpecialVictimsUnit'' '''except''' ''Chicago Med.''

** Maggie Doyle offhandedly mentions that she's a vegetarian--"No meat, no men." Her actress, Jorja Fox, is one as well, as was her character in ''Series/{{CSI}}'', Sara Sidle.

** The show was going to be set in Boston until it was realized that this was too similar to ''Series/StElsewhere''.

* TheCastShowoff: Yvette Freeman would get to sing about OnceASeason, often in the ChristmasEpisode. In the last few seasons, the torch passed to Scott Grimes.

* RoleEndingMisdemeanor: Lisa Nicole Carson, who plays Carla Reese (the mother of Benton's son), had concurrent roles in both ''ER'' and ''Series/AllyMcBeal''. She was fired from both shows for drug use and erratic behavior, as well as being in and out of mental hospitals. The ''ER'' producers were tired of her "unpleasant attitude."
* StarMakingRole:

** Both Michael Michelle and Creator/ThandieNewton and their respective characters, Cleo and Kem, are biracial, though the mixes are different--Michael and Thandie's fathers are white, while Cleo and Kem's mothers are.

** Creator/LisaZane tested for the part of Susan. She would later play one of Doug's temporary love interests.
** Creator/LauraInnes auditioned for the role of said love interest before being cast as Kerry.

** Creator/KatDennings was 19 when she played 14-year-old Zoe Butler, Ray's [[JailBait underaged groupie]], in Season 12.

** Creator/NoahWyle (John Carter) and Kellie Martin (Lucy Knight) did not get along, resulting in her character not being used very much or developed (once he nixed plans for her to be his girlfriend)[[note]]To be fair, he also [[JerkassHasAPoint truthfully pointed out]] that such a relationship would be inappropriate (she was a third-year medical student while he was a second-year resident, therefore she was his subordinate) and out of character for Carter[[/note]].
** Wyle's attitude apparently also affected other co-stars--he has admitted to being hostile to other newcomers such as Erik Palladino and Michael Michele. Reportedly, when Wyle once complained about the buffet for cast and crew, Goran Visnjic (Luka Kovac) snapped "How dare you complain about this food when there are people all over the world who would give their lives for a fraction of what you have!" (Apparently this was due to the Croatian Visnjic's experiences as a veteran of the UsefulNotes/TheYugoslavWars.)

** In 1995, Rachel Greene celebrates her 6th birthday. Assuming a birth year of 1989, by 2001 Rachel would have been 12. Creator/YvonneZima, who had played Rachel up to this point and who was exactly 12, was replaced by 14-year-old Hallee Hirsh.

* DisabledCharacterDisabledActor: Matthew Watkins, who plays Reese, is deaf in RealLife.

** Creator/GeorgeClooney sprained his ankle prior to filming the Season 3 episode "Whose Appy Now?" Ergo, so did his character Doug. This also resulted in a hilarious IronyAsSheIsCast moment when he and Kerry are limping down the hall in tandem and she snaps at him before he explains his predicament. ''Her'' limp is the fake one, as Laura Innes is not disabled in RealLife.

* CastTheRunnerUp: Creator/JuliannaMargulies originally read for the part of Mark's first wife Jen.

** Creator/LisaZane tested for the part of Susan. She would later play one of Doug's temporary love interests.
** Laura Innes auditioned for the role of said love interest before being cast as Kerry.

* A number of actors initially cast in recurring roles were offered or considered being upped to regular status but either declined the offer or didn't end up working out. These include Michael Ironside, Leland Orser, Jorja Fox, CCH Pounder, Ron Eldard, Busy Phillips and Glenn Howerton, among others.

** In 1995, Rachel Greene celebrates her 6th birthday. Assuming a birth year of 1989, by 2001 Rachel would have been 12. Yvonne Zima, who had played Rachel up to this point and who was exactly 12, was replaced by 14-year-old Hallee Hirsh.
** In Season 7, Carter is relentlessly teased for dating Rena Trujillo, a 19-year-old Pediatric intern. Her actress, Lourdes Benedicto, was actually 26 at the time, and is only three years younger than Creator/NoahWyle.

** 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.

** Glenne Headly was pregnant when she played Abby Keaton in Season 3, but this was disguised with surgical scrubs, having her frequently sitting or lying down and placing her behind counters or gurneys.

* CulturalTranslation: The Brazilian dubber for George Clooney is a doctor, so he would also watch the episodes before the dub to add medical translation tidbits for the country (i.e. when they prescript a drug, the dub would mention a local equivalent).

** Julianna Margulies originally read for the part of Mark's first wife Jen.

** Goran Visnjic and his character Luka Kovac not only both hail from Croatia, they had traumatic experiences in UsefulNotes/TheYugoslavWars. (Though Luka's experiences were as a doctor, not a combatant, and far worse than Goran's--losing his entire family).

* TheDanza: In [=S06E07=] "Humpty Dumpty", Rosalind Chao plays a neurologist called Doctor Chao.

* RoleEndingMisdemeanor: Lisa Nicole Carson, who plays Carla Reese (the mother of Benton's son) had concurrent roles in both ''ER'' and ''Series/AllyMcBeal''. She was fired from both for drug use and erratic behavior, as well as being in and out of mental hospitals. The ''ER'' producers were tired of her "unpleasant attitude."

** Also counts to a lesser extent for Julianna Marguiles, Creator/NoahWyle and Mekhi Phifer.

* WrittenInInfirmity: The RealLife pregnancies of several of the show's actresses--Creator/MingNaWen, Creator/AlexKingston, and Sherry Stringfield--resulted in their characters being pregnant as well.
** Creator/GeorgeClooney sprained his ankle at some point in Season 3. Ergo, so did his character Doug. This also resulted in a hilarious IronyAsSheIsCast moment when he and Kerry are limping down the hall in tandem and she snaps at him "that's not funny" before he explains his predicament--HER limp is the fake one! (Laura Innes isn't disabled in RealLife).

* McLeaned: Lucy Knight was murdered by a schizophrenic patient in Season 6 when her actress Kellie Martin wanted to leave the show. In [[https://web.archive.org/web/20170906204755/https://www.vox.com/2017/9/6/16257986/er-lucy-death-kellie-martin this 2017 Vox interview]], Martin explained that she felt working on a medical drama only one week after losing her younger sister to lupus hit too close to home.

** Subverted with Ming-Na (Jing-Mei Chen) and Alex Kingston (Elizabeth Corday). Although their pregnancies were written in, the actresses were much further along than their characters, resulting in this trope for several months until they could catch up.
* HostilityOnTheSet: Noah Wyle (John Carter) and Kellie Martin (Lucy Knight) did not get along, resulting in her character not being used very much or developed (once he nixed plans for her to be his girlfriend) [[note]] To be fair, he also [[JerkassHasAPoint truthfully pointed out]] that such a relationship would be inappropriate (because she was a student) and out of character for Carter. [[/note]] and her deciding to leave the show.

* McLeaned: [[spoiler:Lucy Knight]] was murdered by a schizophrenic patient when her actress [[spoiler:Kellie Martin]] wanted to leave the show, wanting to pursue other projects as she'd never really fit in during her time on the show.

** Wyle's attitude apparently also affected other co-stars--ge has admitted to being hostile to other newcomers such as Erik Palladino and Michael Michele. Reportedly, when Wyle once complained about the buffet for cast and crew, Goran Visnjic (Luka Kovac) snapped "How dare you complain about this food when there are people all over the world who would give their lives for a fraction of what you have!" (Apparently this was due to the Croatian Visnjic's experiences as a veteran of the UsefulNotes/TheYugoslavWars.)

** Wyle's attitude apparently also affected other co-stars. Reportedly, when Wyle once complained about the buffet for cast and crew, Goran Visnjic (Luka Kovac) snapped "How dare you complain about this food when there are people all over the world who would give their lives for a fraction of what you have!" (Apparently this was due to the Croatian Visnjic's experiences as a veteran of the UsefulNotes/TheYugoslavWars.)

* IWantYouToMeetAnOldFriendOfMine: Often times special guest stars will be actors that share a relationship with at least one member of the main cast, although unlike most examples of the trope, the guest stars rarely, if ever, interact with the actor they have a previous relationship with. Notable examples include:
** Creator/MiguelFerrer--Creator/GeorgeClooney's cousin--as a lung cancer patient in the {{Pilot}}, treated by Susan.
** Rosemary Clooney--Clooney's aunt--as a Broadway singer and Alzheimer's patient in Season 1, treated by Carter.
** Julianna Marguiles and Ron Eldard had been dating for several years before he was cast as Carol's paramedic boyfriend Shep in Season 2.
** Creator/GoranVisnjic worked with Clooney in ''Film/ThePeacemaker'' two years before he joined the cast as Luka Kovač in Season 6 following Clooney's departure.
** Diane Baker--Kellie Martin's co-star in the 1998 CBS TV movie ''About Sarah''--as the daughter of a Parkinson's patient in Season 6, treated by Jing-Mei and Carter.
** James Cromwell--Anthony Edwards' co-star in ''Film/RevengeOfTheNerds''--as a bishop in four episodes of Season 7, treated by Luka.

* McLeaned: Carla Reese--see RoleEndingMisdemeanor below.

** Creator/MichaelCrichton wrote the {{Pilot}} in 1974, with the intent of it being a film rather than a TV show.