Edited for Syndication: JLU found a new home on the Saban branded Vortexx block. However, it suffered from Saturday Morning edits. From the first episode, guns were given laser sounds, Green Arrow's boxing glove arrow hitting someone was cut, and Black Canary seductively zipping up her boot was cut.
After The Batman began airing during the Unlimited phase, all major characters from that property other than Batman himself were suddenly verboten in JLU; this was referred to as the "Bat-Embargo" by fans. Similarly, the villain Black Manta was banned when Aquamanseemed a go for a series, as were all Teen Titans characters. Fortunately, DC has plenty of characters to use. As a result, viewers got to see more minor and obscure characters, like Deadman, Warlord, and the Seven Soldiers of Victory, who otherwise would have probably been ignored.
The episode "Legends" was originally supposed to feature the JSA, but DC management informed the show's producers that they could not use the JSA (they were trying to establish the comics as a non-parody group, which the episode would have been counterproductive) and the show had to come up with the expies that were used in the episode proper. Footage of the animated JSA leaked online, however, and a team picture can be found Pic here.◊
Hawk and Dove are voiced by Fred Savage and Jason Hervey, previously known as Kevin and Wayne Arnold on The Wonder Years. Except Wayne's playing the pacifist now; originally, their roles were supposed to reflect their roles on The Wonder Years, but the actors decided to switch.
Series regulars Phil LaMarr (Green Lantern) and Maria Canals (Hawkgirl) replaced respectively Michael Dorn and Lori Petty as Steel and Livewire, also respectively (though Dorn did reprise his role as Kalibak).
Post Script Season - The third season of JLU. Notice the frequency of more out-there episodes and characters.
Promoted Fanboy: Phil LaMarr as John Stewart/Green Lantern. He proudly boasted that for "In Blackest Night," he didn't need his script when reciting the Green Lantern oath.
Also Phil Morris was a huge comic book fan and didn't need to be told anything about Vandal Savage before he voiced him.
Screwed by the Network - The show consistently put out some of Cartoon Network's best ratings in spite of the fact that it was rarely advertised, chronically shoved into unusual timeslots (six in the evening on a Saturday?!), and only aired once a week (most of Cartoon Network's other shows at this time aired reruns several times a week).
When the last season premiered in September 2005, Cartoon Network aired new episodes in an hour timeslot on Toonami. So, four episodes out of the thirteen ordered were burned off in two weeks... and new episodes didn't resume until the following February. And in-between, reruns were non-existent.
Throw It In - It was implied that Cheetah was killed by Solomon Grundy in "Injustice For All", but when the animators mistakenly drew her being arrested at the end of the episode, it was simply easier to say she was alive.
What Could Have Been - Numerous plots and ideas were dreamed up by the writers, and some even went to the scripting and storyboarding stage, before they had to be abandoned for one reason or another before the actual episodes were produced. These include, but are not limited to:
The Crime Syndicate, a not-quite-Evil Twin version of the League from a parallel world, was scheduled to appear in two separate stories, but both were abandoned for different reasons.
The first was "A Better World," an episode where the Syndicate was replaced by the Justice Lords, a more direct mirror image of the League which featured alternate versions of the same characters, rather than villains who were merely similar in theme and power.
The direct-to-DVD film Justice League Crisis On Two Earths is based on the film that was originally supposed to bridge the gap between Justice League and Unlimited.Justice League: Worlds Collide would have explained the origins of the expanded roster, the new Watchtower, and Wonder Woman's invisible jet and would have featured the Crime Syndicate as the primary villains. Worlds Collide was never produced as such, but people on the Crisis on Two Earths production team have said that the film stays within "95 percent" of the original script, and indeed it shows things like the second Watchtower under construction, the beginnings of an expanded Justice League, subtle evidence that Hawkgirl recently left the League, and the origin of Wonder Woman's invisible jet (which made its first DCAU appearance two episodes into Unlimited).
The Birds Of Prey would have starred in an episode of Justice League Unlimited. In a semi-retelling of the origin of Oracle and the team there was originally a plan for Batgirl to be hospitalized in an episode and, unable to finish the mission she was on when she was injured, she would contact Huntress and Black Canary to help her finish the job while supervising them over their radios. The "Bat-Embargo," which was a moratorium on using certain Batman-related characters after the premier of The Batman and the production of Batman Begins, meant that Batgirl had to be written out of the episode and the story was re-written and expanded into "Double Date". The episode still featured Huntress and Black Canary, but also included their "dates" The Question and Green Arrow.
The commentary for "The Return" reveals that, when "Starcrossed" was scripted, the writers did not know where Shayera had gone after leaving the League. One theory was that she had become the resident guardian angel of a small South American village, and another was that one of the victim planets of the Thanagarians had found her seeking revenge (This story was later used in the Unlimited episode "Hunter's Moon"). Eventually they decided that she had sought sanctuary with Doctor Fate, and this led to the double meaning of the title "The Return".
Lastly, a minor cameo instead of a plot-important appearance, the writers originally wanted a Joker cameo in "This Little Piggy" for a brief moment of comic relief. After Diana had been turned into a pig, Batman would be walking down the street with her and would pass the Joker preparing to commit a crime with his gang. The Joker, in the middle of preparing a heist and laying out his convoluted plan to deal with Batman, would see Batman holding and consoling a pig and would stare at it in Dull Surprise, then throw his hands in the air and abandon the entire scheme. Sadly, this scene (Which might very well have been the single greatest scene ever animated), had to be dropped from the episode for a variety of reasons, including time and pacing problems.