X-Men #141 (1981) "Days of Future Past"! Non-GCGed.
The basic premise of the X-Men, the prejudice leveled against "heroes sworn to protect a world that fears and hates them," was always a thinly-disguised metaphor for racism. In "Days of Future Past" that is expanded and focused to more precisely relate to antisemitism, and arguably homophobia as well, with mutants in the future herded into concentration camps, and those who survive forced to wear emblems identifying their "crime." Though is this case, instead of gold Stars of David and pink triangle patches it's jumpsuits emblazoned with the letter "M."
From this world, an adult Kitty Pryde - though by this time she goes by "Kate" - is sent back in time to stop the pivotal event that turns the world against mutants: the high-profile assassination of presidential candidate Senator Robert Kelly by the new Brotherhood of Evil Mutants.
The "future" portions of this story are set in 2013, which must have seemed safely "future" in 1980 when this story was written (despite its January 1981 cover date, X-Men #141 went on-sale in September 1980).
X-Men #141 contains the first appearance of the villains Avalanche, Pyro and Destiny. Also the first appearance of Rachel Summers, the alternate-timeline daughter of Scott Summers and Jean Grey who will go on to a long career as a Marvel Comics superheroine in her own right.
The cover to this issue, on which an older Wolverine and Kate Pryde are speared by a searchlight while behind them a series of wanted posters shows all the X-Men and other associated characters who've been captured or killed, has become one of the most-homaged cover drawings in comic book history.
It would impossible to overstate the importance to Marvel of the story contained in this issue, and the next. Entire forests have been felled to print Marvel Comics tales flowing from the events of "Days of Future Past." Also, this story provided the basic plot idea for the movie X-Men: Days of Future Past - though in the film it's Kitty Pryde who sends Wolverine
back in time, to save the future by changing the past, instead of Kitty
herself being sent back by Rachel Summers.
The probable inspiration for the title "Days of Future Past" is The Moody Blues' 1967 album Days of Future Passed, a concept album where the "concept" is an attempt to understand the cycles of life through examining a single day. In the X-Men story, Kate Pryde in the body of her younger self doesn't even have an entire day, she has only a few hours to prevent the dystopian future she's occupied from coming to be.
Though the second part of story, appearing next issue, is titled "Mind Out of Time" there is a tendency among comic book fans to refer to the entire two-part story as "Days of Future Past."
This is the last issue before the title of the book officially changes to The Uncanny X-Men, though "Uncanny" has been included in the cover title of almost every issue since #114, the only exceptions being #s 137 and 138 when a contest banner forced "The Uncanny" to be removed.
I am very serious that a buyer gets their comic in
the condition it was when I sent it. All my comics are mailed inside an
acid-free Mylite, with acid-free backing board, inside a Gemini mailer,
with two filler pads inside the mailer with the book.
X-Men #141: Cover date January 1981, written by Chris Claremont, penciled and co-plotted by John Byrne, inked by Terry Austin, lettered by Tom Orzechowski, colored by Glynis Wein.