Avengers

The Avengers are a team of superheroes, Earth's Mightiest Heroes, based in New York City. Led by Captain America and including such members as Iron Man and Hulk, they are the Earth's foremost defense against superpowered threats. The team is headquartered in either the Avengers Mansion, or the replica version of Stark Tower, now called Avengers Tower.

"One on one, we can each take down a villain or two, but 74... none of us can do it alone. Together we have a chance. What we did here, it can change things. The world needs us, but not as S.H.I.E.L.D. agents. As a team of our own. Together, we can avenge the wrongs caused by all these villains." "We can be Avengers."
 * —Captain America and Wasp.

Known members of the Avengers

 * Steve Rogers/Captain America (Leader)
 * Tony Stark/Iron Man
 * Thor Odinson/Thor
 * Dr. Robert Banner/Hulk
 * Janet van Dyne/Wasp
 * Clinton Barton/Hawkeye
 * Carol Danvers/Ms. Marvel
 * T'Challa/Black Panther
 * Vision
 * Henry Pym/Yellowjacket
 * Natasha Romanoff/Black Widow
 * Samuel Wilson/Falcon
 * Scott Lang/Ant-Man

Reserve Members

 * Peter Parker/Spider-Man

Affiliated Allies

 * Guardians of the Galaxy
 * Winter Guard
 * JARVIS
 * Pepper Potts
 * S.H.I.E.L.D.
 * Geheneris Hala´son Mar-Vell/Captain Marvel
 * Faradei
 * Warriors Three
 * Sif and her Valkyries

Equipment

 * All Members
 * Quinjets (destroyed)
 * Aven-Jet Prime (destroyed)
 * Avengers ID Card
 * Sky-Cycle
 * Iron Man
 * Iron Man's armor
 * Captain America
 * Captain America's Shield
 * Thor
 * Mjolnir
 * Hawkeye
 * Hawkeye's Bow and Trick Arrows
 * Black Widow
 * Black Widow's Gauntlets
 * Falcon
 * Red-Wing Armor
 * Redwing
 * Spider-Man
 * Web Shooters
 * Ant-Man 
 * Ant Helmet
 * Pym-Particle Blaster
 * Size Alteration Suit

History
In the early days since their formation, the Avengers encountered and fought Molecule Man, a short but difficult battle they won.

At some point in time, the Avengers split up and went their separate ways; the reason being unknown. It's unknown who else was in the Avengers prior to the series; because when Steve Rogers took over as leader he tells the others that the Avengers were coming back, handpicked by him. Meaning that there were more members then the seven current members.