In the years 1965 through 1967, Stan Lee and his art partner Don Heck guided the Avengers through their "Kooky Quartet" era with unbridled adventures and important character development. Hawkeye, Scarlet Witch, Quicksilver, and Captain America took on all comers, often in multi-part epics that pitted the Avengers against foes old and new, like the Enchantress, Doctor Doom and Kang.

The Avengers of 1965-1967 also featured change within the ranks of the team and its creative stable. The Wasp and Giant-Man would rejoin Earth's Mightiest-the latter adopting a new costume and codename-and Black Widow and Hercules would join as guest stars. Lee would depart as writer in the summer of 1966, handing the keys to the Avengers over to newcomer Roy Thomas, whose earliest stories set the stage for his future glories carrying the title to a legacy filled with milestone after milestone.

Avengers Nos. 21-40 are collected here in a volume that closely simulates the size and proportions of the original comic artboards; with comics sourced from the collection of Bob Bretall, holder of the Guinness World Record for largest comics collection, meticulously photographed to resemble the way these comics looked when first published, while also being digitally remastered using modern retouching techniques to correct problems with the era's imperfect printing. A custom paper stock was developed exclusively for this series to replicate the newsprint feel and color holding of the original comics. The Marvel Comics Library has earned well-deserved raves for combining an old school reading experience with a luxurious oversized book format, winning the industry's coveted Eisner Award for Best Publication Design.

Complementing the comics is an essay by Black Panther writer Christopher Priest, whose lively style merges with a deep and abiding love for the comic book artform and its history. Accompanying his essay is a gallery of original art, photographs, rarities, and other ephemera of the era.Also available in a Collector's Edition of 1,000 numbered copies