Short answers, pulled from the story.
The Avengers comic team was created by Stan Lee and Jack Kirby in the autumn of 1963. Loki, the Asgardian god of mischief, manipulated a young teenager named Rick Jones into gathering Iron Man, Ant-Man, the Wasp, the Hulk, and Thor to stop him, which led to the formation of the group.
The Avengers first appeared in a comic book with a cover date of September 1963. The first issue featured art by Jack Kirby and Dick Ayers and launched a legacy that would redefine the superhero genre.
Captain America was discovered by the Avengers in March 1964 during the fourth issue of their series. This event was so significant that Captain America was retroactively granted founding member status, replacing the Hulk who had left the team after a single issue.
The Scarlet Witch went insane after agonizing over the memory of her lost children and subsequently lost control of her reality-altering powers. This event led to the deaths of some team members and the disbanding of the original Avengers team.
The Marvel Cinematic Universe Avengers films have collectively grossed over 26 billion dollars in box-office revenue. The franchise began in 2008 with the film Iron Man and culminated with the release of The Avengers in 2012.