This post is different than most. It is more of a reference than a map. I will be cataloging the first 45 issues of Classic X-Men, making notes of the backup stories, and where they might take place, and also where they themselves might have been reprinted.
Classic X-Men #1 (Giant Size X-Men #1)
-Back-up: “First Night” – the night after the Krakoa mission at the X-Mansion
-Placement: immediately before and after GSX #1
-Notes: Not a good reprint source for Giant Size X-Men #1 (only includes the first chapter). Only CXM issue to include new material at the very front of the book, however the only instance I can verify of those 4 pages ever being reprinted are in the Giant Size X-Men 40th Anniversary edition.
-Reprinted: X-Men Vignettes Volume 1, X-Men: Original Sin #1, X-Men Rarities TPB, Giant Size X-Men 40th Anniversary HC, Classic X-Men: Complete Collection Volume 1
Classic X-Men #2 (Uncanny X-Men #94)
-Back-up story: Storm and Jean develop their friendship
-Placement: The second chapter of #94 continues directly into #95, so this backup takes place in between the two chapters of #94.
-Reprinted: X-Men Vignettes Volume 1, Classic X-Men: Complete Collection Volume 1
Classic X-Men #3 (Uncanny X-Men #95)
-Back-up story: Thunderbird’s funeral
-Placement: Immediately after UXM #95
-Reprinted: X-Men Vignettes Volume 1, X-Men: Lost Tales #1, Giant Size X-Men #4, Classic X-Men: Complete Collection Volume 1
Classic X-Men #4 (Uncanny X-Men #96)
-Back-up story: Wolverine and Nightcrawler
-Placement: no reason to move it out of sequence.
-Reprinted: X-Men Vignettes Volume 1, , Classic X-Men: Complete Collection Volume 1, X-Men: Lost Tales #1, Marvel Super-Hero Team-Up TPB
Classic X-Men #5 (Uncanny X-Men #97)
-Back-up story: Colossus
-Placement: no reason to move it out of sequence (I believe the girl in the story is referenced in the extra material added in CXM #6.)
-Reprinted: X-Men Vignettes Volume 1, X-Men: Lost Tales #1, Colossus: God’s Country TPB, Classic X-Men: Complete Collection Volume 1
The stories in CXM #4-5 were designed to show the new X-Men bonding as a team and getting used to their new lives, and could fit almost anywhere between UXM #94 and #98.
Classic X-Men #6 (Uncanny X-Men #98)
-Back-up story: Jean Grey gets ready for date night.
-Placement: Immediately before UXM #98.
-Reprinted: X-Men Vignettes Volume 1, Classic X-Men: Complete Collection Volume 1
Classic X-Men #7 (Uncanny X-Men #99)
-Back-up story: Hellfire Club
-Placement: Opening caption places in between Christmas and New Year’s, likely on New Year’s Eve itself.
-Reprinted: X-Men Vignettes Volume 1, Classic X-Men: Complete Collection Volume 1
Classic X-Men #8 (Uncanny X-Men #100)
-Back-up story: origin of the Phoenix
-Placement: immediately after UXM #100 (partial overlap)
-Reprinted: X-Men Vignettes Volume 1, Phoenix Rising TPB/HC, Classic X-Men: Complete Collection Volume 1
Classic X-Men #9 (Uncanny X-Men #101)
-Back-up story: Nightcrawler meets a boy at the hospital while waiting for word on Jean’s condition.
-Placement: in the middle of UXM #101, between the airport and hospital scenes.
-Reprinted: X-Men Vignettes Volume 1, Classic X-Men: Complete Collection Volume 1
A quick note about the timeline during this sequence. First, Uncanny X-Men #98 to #101 show a continuous sequence of events. UXM #98 starts on Christmas Eve, then jumps to Sunday, December 28. The X-Men return from space in #101, although no time reference is given in the original story. However, there is a gap between the airport and hospital scenes in #101 where the Classic #9 back-up story obviously occurs. That story is captioned as “Wednesday morning, 3 AM” but also states “the New Year well and truly begun”. Well, if December 28 was a Sunday, Wednesday would only be December 31. Assuming the Wednesday caption really should be Thursday, that implies that the X-Men returned from space on either December 30 or 31, spending the next two days or so at the hospital. (The first hospital scene has a caption explaining that day moves to night into day again, and it’s possible that they had already spent one day at the hospital.) The Hellfire Club back-up story in Classic #7 likely goes in the same gap during #101, occurring before the Classic #9 back-up.
Classic X-Men #10 (Uncanny X-Men #102)
-Back-up story: Wolverine vs. Sabretooth
-Placement: Based on captions on the first page, it implies it is very early in Wolverine’s tenure in the X-Men, as he’s been sizing up NYC for the better part of a week. According to the Classic X-Men Complete Collection, it takes place during UXM #94.
-Reprinted: X-Men Vignettes Volume 1, X-Men: Lost Tales #2, Sabretooth Classic #12, Classic X-Men: Complete Collection Volume 1
Classic X-Men #11 (Uncanny X-Men #103)
-Back-up story: Storm meets the suicidal writer.
-Placement: near impossible due to continuous string of events in main UXM stories. The Complete Collection says it takes place between UXM #103-104.
-Reprinted: X-Men Vignettes Volume 1, Classic X-Men: Complete Collection Volume 1
Classic X-Men #12 (Uncanny X-Men #104)
-Back-up story: Magneto flashback.
-Placement: anytime after UXM #104.
-Notes: It could remain in sequence, as long as it takes place between UXM #104 and #111. In one version of a map, I moved it to some point after UXM #108 to keep the Phoenix Saga sequence together.
-Reprinted: X-Men Vignettes Volume 1, X-Men: Lost Tales #1, Magneto #0, Classic X-Men: Complete Collection Volume 1
Classic X-Men #13 (Uncanny X-Men #105)
-Back-up story: Phoenix and Misty Knight
-Placement: UXM #105-108 form a continuous narrative sequence. I originally placed it prior to UXM #105, but the Complete Collection states it takes place between #110-111.
-Reprinted: X-Men Vignettes Volume 1, True Believers: Phoenix Classic #1, Classic X-Men: Complete Collection Volume 1
Classic X-Men #14 (Uncanny X-Men #107)
-Back-up story: Lilandra’s backstory.
-Placement: Chronologically, this story leads up to Lilandra’s first appearance in Xavier’s dreams in UXM #97. Or, it could be read as a flashback after UXM #108. The Complete Collection says it takes place during UXM #65-66.
-Reprinted: X-Men Vignettes Volume 2, Classic X-Men: Complete Collection Volume 1
Classic X-Men #15 (Uncanny X-Men #108)
-Back-up story: Starjammers backstory.
-Placement: It’s completely a flashback, so it can be moved at the binder’s discretion.
-Reprinted: X-Men Vignettes Volume 2, Classic X-Men: Complete Collection Volume 1
Classic X-Men #16 (Uncanny X-Men #109)
-Back-up story: Black Tom and Banshee backstory.
-Placement: in the past.
-Reprinted: X-Men Vignettes Volume 2, Classic X-Men: Complete Collection Volume 1
Classic X-Men #17 (Uncanny X-Men #111)
-Back-up story: Mesmero
-Placement: Immediately before UXM #111.
-Notes: Unfortunately, to move the backup story into the proper place, scanning and printing is required as the main story and back-up story are printed back-to-back.
-Reprinted: X-Men Vignettes Volume 2, X-Men: Lost Tales #2, Classic X-Men: Complete Collection Volume 1
Classic X-Men #18 (Uncanny X-Men #112)
-Back-up story: Phoenix and Wolverine go camping.
-Placement: Due to the continuous sequence of UXM #111-121, this story would take place on either side of those issues. The Complete Collection places it before UXM #111, shortly after CXM #13.
-Notes: Written by Jo Duffy.
-Reprinted: X-Men Vignettes Volume 2, True Believers: Phoenix Classic #1, Classic X-Men: Complete Collection Volume 1
Classic X-Men #19 (Uncanny X-Men #113)
-Back-up story: Magneto’s origin.
-Placement: Flashback, no present day link.
-Reprinted: X-Men Vignettes Volume 2, Magneto #0, Classic X-Men: Complete Collection Volume 1
Classic X-Men #20 (Uncanny X-Men #114)
-Back-up story: Storm’s nightmare.
-Placement: not in sequence, no context. Complete Collection places it between UXM #128-129.
-Notes: Written by Jo Duffy. Final page of story is on inside of back cover.
-Reprinted: X-Men Vignettes Volume 2, Classic X-Men: Complete Collection Volume 1
Classic X-Men #21 (Uncanny X-Men #115)
-Back-up story: Colossus in the Savage Land.
-Placement: middle of UXM #115
-Reprinted: X-Men Vignettes Volume 2, X-Men: Lost Tales #2, Colossus: God’s Country TPB, Classic X-Men: Complete Collection Volume 1
Classic X-Men #22 (Uncanny X-Men #116)
-Back-up story: Storm in the Savage Land.
-Placement: before the last page of UXM #116
-Reprinted: X-Men Vignettes Volume 2, Classic X-Men: Complete Collection Volume 1
Classic X-Men #23 (Uncanny X-Men #117)
-Back-up story: Nightcrawler’s adventure
-Placement: in sequence.
-Reprinted: X-Men Vignettes Volume 2, X-Men: Lost Tales #2, Classic X-Men: Complete Collection Volume 1
Classic X-Men #24 (Uncanny X-Men #118)
-Back-up story: Phoenix on vacation.
-Placement: Since UXM #118-119 is continuous, it’s best moved prior to UXM #118.
-Reprinted: X-Men Vignettes Volume 2
Honestly, from this point on, most of the back-up stories just become filler material, especially as Claremont only writes a handful. There’s probably a good reason why a third volume of Vignettes was never produced. The only remaining CXM stories that have been reprinted either tie into Proteus or Dark Phoenix directly, or was drawn by Jim Lee.
Classic X-Men #25 (Uncanny X-Men #119)
-Back-up story: Wolverine goes hunting
-Placement: no context.
-Notes: Written by Ann Nocenti.
-Reprinted: X-Men Vignettes Volume 2
Classic X-Men #26 (Uncanny X-Men #120)
-Back-up story: Wolverine in a bar.
-Placement: no context.
-Notes: Written by Tom Orzechowski.
Classic X-Men #27 (Uncanny X-Men #121)
-Back-up story: Creatures from the drain.
-Placement: No context.
-Notes: This is the last issue to feature additional material in the main story. Written by Ann Nocenti.
Classic X-Men #28 (Uncanny X-Men #122)
-Back-up story: X-Men at a costume party.
-Placement: No context, but needs to be moved due to the continuous sequence of UXM #122-124.
-Notes: Written by Ann Nocenti.
Classic X-Men #29 (Uncanny X-Men #123)
-Back-up story: Colossus visits mother Russia
-Placement: Due to continuous story in UXM #122-124, this story should be moved to either side of that arc.
-Notes: Shares page with main story.
-Reprinted: Colossus: God’s Country TPB
Classic X-Men #30 (Uncanny X-Men #124)
-Back-up story: Arcade
-Placement: Can take place in sequence.
-Notes: Written by Ann Nocenti. Shares page with main story.
Classic X-Men #31 (Uncanny X-Men #125)
-Back-up story: Professor X in space.
-Placement: Could take place in sequence, as it has no bearing on the main story. Could be viewed as “meanwhile”.
-Notes: Written by Ann Nocenti. Shares page with main story.
Classic X-Men #32 (Uncanny X-Men #126)
-Back-up story: Proteus warps reality.
-Placement: In sequence, expands on main story.
-Notes: Written by Ann Nocenti. Shares page with main story.
-Reprinted: X-Men: Proteus HC
Classic X-Men #33 (Uncanny X-Men #127)
-Back-up story: Havok and Polaris during Proteus battle.
-Placement: Between pages 4-5 of main story.
-Notes: Written by Ann Nocenti. Shares page with main story.
-Reprinted: X-Men: Proteus HC
Classic X-Men #34 (Uncanny X-Men #128)
-Back-up story: White Queen/Hellfire Club.
-Placement: Could take place in sequence.
-Notes: Written by Ann Nocenti. Shares page with main story.
Classic X-Men #35 (Uncanny X-Men #129)
-Back-up story: Kitty Pryde dream sequence.
-Placement: Between pages 14-15 of UXM #129
-Notes: Written by Daryl Edelman.
Classic X-Men #36 (Uncanny X-Men #130)
-Back-up story: Moira dealing with Proteus aftermath.
-Placement: Some time after the opening of UXM #129, probably best after UXM #131 to minimize interuption.
-Notes: Written by Fabian Nicieza.
-Reprinted: X-Men: Proteus HC
Classic X-Men #37 (Uncanny X-Men #131)
-Back-up story: A Dazzler solo adventure.
-Placement: Can take place in sequence.
-Notes: Written by Fabian Nicieza.
Classic X-Men #38 (Uncanny X-Men #132)
-Back-up story: Another Dazzler adventure.
-Placement: Um….? Don’t bother.
-Notes: Written by Ann Nocenti.
Classic X-Men #39 (Uncanny X-Men #133)
-Back-up story: focused on Storm.
-Placement: Context free. I doubt it should be placed within the confines of the Dark Phoenix Saga.
-Notes: Written by Ann Nocenti. Honestly, the only reason anyone remembers this is because Jim Lee drew it.
-Reprinted: X-Men Visionaries: Jim Lee TPB
Classic X-Men #40 (Uncanny X-Men #134)
-Back-up story: Nightcrawler goes people watching.
-Placement: No context.
-Notes: Written by Tom Orzechowski.
Classic X-Men #41 (Uncanny X-Men #135)
-Back-up story: Scott Summers in the orphanage
-Placement: Flashback.
Classic X-Men #42 (Uncanny X-Men #136)
-Back-up story: Another young Cyclops adventure.
-Placement: Flashback.
Classic X-Men #43 (Uncanny X-Men #137)
-Back-up story: Phoenix meets death?
-Placement: in sequence.
-Reprinted: some versions of the Dark Phoenix Saga and Phoenix Rising TPBs/HCs
Classic X-Men #44 (Uncanny X-Men #138)
-Back-up story: Rogue before her first appearance.
-Placement: Depending on Rogue’s personal timeline, this could fit in right here, or slightly in the past.
-Notes: Written by Ann Nocenti.
Classic X-Men #45 (Uncanny X-Men #139)
-Notes: No back-up story, series changes name to X-Men Classic with the following issue.