Trivia: The directors have previously worked on both Community and Arrested Development - both shows get nods in this movie. Jim Rash, the Dean from Community, plays an MIT faculty member at the start. More subtle is the Bluth family's stair-car from Arrested Development, seen briefly as Captain America walks onto the airport runway before the big battle with the other Avengers.
Trivia: There is an extra post-credits sequence with Spiderman.
Trivia: When the film was first announced, it was jokingly called "Captain America: Serpent Society" before its actual title was revealed a few minutes later.
Trivia: At the age of 19, Tom Holland is the youngest actor to play Spider-Man/Peter Parker on the big screen.
Trivia: When Tony Stark is visiting the Raft, an imprisoned Clint Barton mockingly calls him a "futurist." In 2004, Robert Downey Jr. released an album called "The Futurist."
Trivia: Director Joe Russo appears in the film as Dr. Broussard, the murdered psychiatrist hired to interview Bucky. Russo plays a different character than he did in "Captain America: Winter Soldier", but still uses the alias Gozie Agbo in the credits.
Trivia: In the comics, a group of celebrity superhuman vigilantes tried to take down a house of super-villains on television, but one of the villains escaped due to the vigilante's incompetence and blew up a school, killing hundreds of children. At the memorial, which Stark attended, a woman accused him of letting it happen (although he had nothing to do with it), leading him to support the act so that such reckless acts of heroism would not happen again.
Trivia: Stan Lee makes a cameo at the end of the movie as the FedEx man who says "Are you Tony Stank?"
Trivia: After Tony blows off Bucky's arm, Cap picks up his shield and shields himself from Tony's blasts. At the very end of the shot, Tony is firing a beam at Cap which lands on Cap's shield and the shot begins to slow down. This moment from the shot is an homage to the cover from part 7 of the Marvel Civil War comic storyline, where Captain America and Iron Man are fighting on the front cover in the same way. (02:07:00)
Trivia: In the comics Tony Stark and Reed Richards worked to design a superhuman prison known as Prison 42, which was made specifically for super humans who disobeyed the Registration Act. It was top secret and was used to hold many of those on Team Cap about halfway through the arc. Captain America later broke his teammates out of the prison.
Trivia: Sharon Carter says a eulogy at her aunt Peggy's funeral, with the quote from Peggy, "your job is to plant yourself like a tree and say no, you move." This line is actually an iconic quote from the newer Captain America comics, and is said by Captain America, not Peggy Carter. The quote was said in Amazing Spider-Man #237, published in 2007.
Chosen answer: Because the U.N. has been preparing to pass the Sokovia Accords and they want to oversee the Avengers. A week earlier, the Avengers would not have had to seek permission to find the other Winter Soldiers (or wait while the oversight committee makes a decision). As a result of the U.N. Sanctions, Captain America and Sam Wilson have to go rogue in order to find the other soldiers. (Their actions of going rogue result in Iron Man and his team in hunting the rogue Avengers down, creating a "civil war").
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