The answer depends on what you mean by "first." Are you asking about the first Avenger chronologically in terms of the Marvel Cinematic Universe (MCU) timeline, or the first Avenger introduced in the movie release order?
Chronological Order (MCU Timeline)
Captain America, specifically Steve Rogers, is the first Avenger in terms of the MCU's chronological timeline. His story is depicted in Captain America: The First Avenger, which takes place largely during World War II. The movie showcases his transformation and heroic acts during this period, establishing him as the earliest active hero within the MCU timeline.
Movie Release Order
While Captain America is chronologically the first Avenger, Iron Man (Tony Stark) was the first Avenger introduced to audiences in the movie release order. Iron Man (2008) was the first film in the MCU, marking the beginning of the Avengers initiative and introducing the character who would later become a key member of the team.
Summary
Therefore, the "first" Avenger depends on the context:
- Chronologically: Captain America
- Movie Release Order: Iron Man
