Countdown to Endgame: The Foundation of the MCU

But while Iron Man brought crowd-pleasing spectacle and banter, The Incredible Hulk was packed with nods and references to the comics, including images taken straight from the source material. And, as the second film in the MCU, the movie began to lay the groundwork for the nascent shared universe with references to S.H.I.E.L.D., Nick Fury, Captain America and an appearance by Tony Stark himself.

In lieu of a post-credits scene (it's the only MCU film without one), Robert Downey Jr. briefly reprised his role as Stark while hinting at the possibility of starting the Avengers. After the scene was included in the film's marketing, it was moved to the end of the main part of the film. While receiving much better critical reviews than the 2003 Hulk, The Incredible Hulk only earned $236.4 million at the worldwide box office, cementing it as the weakest commercial performance in the MCU to date.

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As pre-production stalled on Thor and Captain America solo films, with Matthew Vaughan exiting Thor in 2008 and Captain America: The First Avenger delayed by a writers' strike, Marvel Studios fast-tracked a sequel to Iron Man. Favreau and much of the principal cast returned, though Terrance Howard's James Rhodes was recast with Don Cheadle, with reports claiming Howard and Marvel could not reach an agreement on the actor's salary on top of concerns over his performance in the first film.

The sequel also introduced audiences to Black Widow and gave Nick Fury a much larger role after publicized salary negotiations between Samuel L. Jackson and Marvel Studios. Impressed by the buzz for the sequel, the success of its predecessor and the company's vast library of characters, Disney bought Marvel in August 2009, one month after principal photography on Iron Man 2 officially wrapped.

While critics were divided by the film's themes of self-destruction and denial in the face of mounting responsibility, the sequel was the biggest commercial hit in the MCU at the time, outperforming the original film by a significant margin. Given the nature of Tony Stark facing his own impending mortality and need to create a legacy, the character intentionally comes off as less likable than ever, which put off viewers but established the need for redemption in a character that had just been redeemed one film prior.

It was now clear that, despite the minor underperformance of The Incredible Hulk, the MCU was no one-hit wonder. Production on the final films leading up to the promised ensemble would commence before Iron Man 2 was even released, and the sequel's strong box office boosted the momentum for Marvel Studios. This vote of confidence would prove especially invaluable as the studio took its biggest risks ever with its following three films.

Directed by Anthony and Joe Russo, Avengers: Endgame stars Robert Downey Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, Jeremy Renner, Don Cheadle, Paul Rudd, Brie Larson, Karen Gillan, Danai Gurira, Benedict Wong, Jon Favreau and Bradley Cooper, with Gwyneth Paltrow and Josh Brolin. The film arrives April 26.

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