For the first few decades of his comic book history, Spider-Man was much more of a solo act than a team player. Within recent years, however, Peter Parker has joined several teams, like the Avengers or the Future Foundation. Spider-Man became a vital team player during one of his first missions on the New Avengers. The web-slinger first joined the New Avengers in New Avengers #3, by Brian Michael Bendis and David Finch. Since then, the team had been on a couple of missions, traveling to the Savage Land and fighting the Wrecker. Concurrently, Peter's New Avengers exploits were detailed in the Amazing Spider-Man, giving a closer look at the wall-crawler's first days on the team. Everything changed for Peter in Amazing Spider-Man #519, by J. Michael Straczynski and Mike Deodato.
When Aunt May's home in Forest Hills was destroyed, Tony Stark asked Peter, May and Mary Jane to move in to Avengers Tower. This was a pretty big step for Peter, who not only shared his secret identity with his teammates, but shared a living space with some of them. Aunt May and MJ also got to live in the center of Peter's superhero life, which was a major shift from the status quo.
From here, it didn't take long for sinister forces like HYDRA to step out of the shadows. HYDRA was looking to regain its former glory, after suffering several defeats. In order to match their enemies' power, HYDRA created the HYDRA Four, enhanced agents who were made to imitate classic Avengers. Captain America, Iron Man, Thor and Hawkeye were all mimicked by HYDRA, sending these super-agents out into the field. After a brief clash with the New Avengers, the HYDRA Four escaped. Spider-Man, with his brilliant mind, knew that HYDRA staged this attack to distract and humiliate the Avengers, while they smuggled something dangerous into the U.S.
Moreover, this new incarnation of HYDRA had killed several of its former leaders for their incompetence in the past. Tracking down one of HYDRA's agents, Spider-Man snuck into the new HYDRA base and learned their plot. Apparently, HYDRA was sending a missile filled with anthrax and plague bacilli to poison the water supply of eight states. After sneaking around the base for a while, Spider-Man was discovered, sending him into conflict with the HYDRA Four.
The web-head held off these agents long enough for his fellow New Avengers to arrive. This way, Spider-Man was free to stop the missile from reaching its target, Ogallala Aquifer. The missile, launched, forcing Spider-Man to hold on long enough to manually disarm the weapon. When the missile detonated over the water, it seemed as if Spider-Man was finished. Fortunately, however, Iron Man arrived to save him. Overall, this mission with the New Avengers demonstrated how far Spider-Man had come as a hero. Peter got to fight alongside Captain America and Iron Man, as part of the same team. As part of the New Avengers, Spider-Man took on HYDRA, a global threat that went beyond villains such as the Sandman or the Vulture. This particular storyline also made Spider-Man its central focus, allowing him to prove his worth both physically and mentally.
Peter boasted his skills in battle, taking on the HYDRA Four all by himself. At the same time, Spider-Man took advantage of his intellect by figuring out HYDRA's plot and shutting it down, almost single-handedly. Intellectually and physically, Spider-Man demonstrated his place on the Avengers. Having a team to back him up, Spider-Man didn't have to face the threat of HYDRA alone, either. It's true that before, Spider-Man had taken on some major threats, and even worked with teams like the Avengers to stop them. Yet this time, Spider-Man was acting in an official capacity, as one of the New Avengers. This is much different from his typical outlaw vigilante status. It was also just nice to see such a drastic change in Spider-Man's overall status quo.
Living in Avengers Tower, Peter's family got to interact with several of Marvel's major characters. Aunt May grew closer with Jarvis and got into fight with Wolverine over his bad manners, while Peter came to view Iron Man and Captain America as his mentors. Of course, it was difficult to maintain Peter's secret identity, since he and his family were living in Avengers Tower. This led to some complications, such as the public believing MJ was having an affair with Tony Stark. Fortunately, rumors like these were cleared up relatively quickly. This was all part of the new normal for Spider-Man, for better or worse. It's a shame that this era didn't last longer for Spider-Man, but at this time, Peter Parker had become a true Avenger.