Collects Giant-Size X-Men #1 and Uncanny X-Men #94-100.

From the publisher:

Celebrate Marvel's 70th anniversary by experiencing the tales of the world's most-famous super heroes from the very beginning! The Marvel Masterworks have brought readers deluxe hardcover collections of Marvel's classics from the Golden Age, Atlas Era, and the mighty Marvel Age, and now you can join in the Masterworks excitement with Marvel's new Marvel Masterworks trade paperbacks.

Go back to the early days of Chris Claremont's legendary run in Marvel Masterworks: The Uncanny X-Men Volume 1. Wolverine, Nightcrawler, Storm, Colossus; Endowed with unique abilities, these mutants were summoned by Professor X to rescue the original X-Men, an underground organization sworn to protect those that fear and hate them. Relive their original adventures - discover the human within the hero and the truth behind the legend!

The Children of the Atom, runts of the Silver Age litter, are reborn as the All-New, All-Different team of mutants that took the world by storm! With the original team held hostage by unknown forces, Professsor X recruits an international cast including Wolverine, Storm, Colossus, Nightcrawler, Banshee, Sunfire and Warpath to take on the mantle of the Uncanny X-Men!

Marked by progressive politics and personal conflicts, these All-New X-Men redefined super-hero teams for a generation of readers that can't get enough X-adventure to this day. Here for the first time you'll see Wolverine throw down with Cyclops; experience the shocking death of an X-Man; tremble at the return of the towering Sentinels; watch as X-Man battles X-Man as the new team attempts to tear apart the old; and bear witness to the sacrifice of Jean Grey. They're mutant milestones of the highest order, one and all - the stories that set the table for a comics revolution - so buy it today, True Believer!

This came from the collection of Steve Sherman, a writer,artist, puppet-maker, puppet-performer, and avid collector. Steve worked as Jack Kirby's assistant, at Filmation, and Sid and Marty Krofft, before forming his own company Puppet Studio in 1984 contributing to "Pee-Wee's Playhouse", "Men in Black 1 & 2", "Mighty Joe Young", "Muppets" and numerous other TV series and feature films.