James and Lily would have finished in the early to mid 80s, right? And I've read fanfic that had Minerva finishing either right before or during WWII, which made sense to me.

Here we go:

Minerva attended Hogwarts School of Witchcraft and Wizardry as a pupil from 1937 to 1944. This would mean that McGonagall was studying as a pupil in the year above Tom Riddle. She was Sorted into Gryffindor House, of which she would later serve as Head in her later life. McGonagall presumably achieved an Outstanding or Exceeds Expectations in Transfiguration, which was taught by Albus Dumbledore, as she would later go on to teach the subject.

She graduated in '44 and returned to teach in '56. So there are twelve missing years in there.

In 1981, baby Harry Potter defeated Lord Voldemort in his family home at Godric's Hollow, his parents James Potter and Lily Evans (both members of the Order of the Phoenix) were killed whilst protecting their son from harm.

So James and Lilly and Snape and the Marauders were students in the 70s.

So Minerva, Riddle and Hagrid and Moaning Myrtle were all classmates, though not in the same class. When Dumbledore was a Transfiguration teacher.

I know there's a lot of Marauders fic but I wonder if there's much about this generation.

I've read some good fic with Minerva and others from Hogwarts fighting in Europe after D-Day against Grindelwald and his supporters--I'll have to see if I can find it.

(I've actually considered writing one that would have only tangetially dealt with Dumbledore at this time. It would have been focused on Grindelwald and would have also tied in the Holocaust, which is why I'm really leery about going there. Jewish wizards would have had it really bad on the continent during this period, between Grindelwald and Hitler.)

Molly and Arthur Weasley started at Hogwarts in the early sixties. Lucius Malfoy overlapped with them as he arrived in the mid sixties with Narcissa (and Bellatrix?), and then Lucius was a prefect when Snape arrived. Molly's two younger brothers who were killed as members of the original Order of the Phoenix were also probably close in age to Lucius, then. Lucius was also in the Slug Club when Slughorn was potions master.

I expect many of the bad guys who take over the Ministry in the later books were originally in Slytherin house in the sixties.

Van you even imagine slytherin in the 60s? Swingin'!

In their groovy underwater pad.

I've read some good fic with Minerva and others from Hogwarts fighting in Europe after D-Day against Grindelwald and his supporters--I'll have to see if I can find it

I would love to see links to these (maybe over on the fic thread? As we're wandering OT for this one). I am weirdly uninterested in Marauder-era stuff, but I love the idea of McGonagall fighting Grindelwald.

slytherin in the 60s?

Oh, the velvet frock coats they must have had.

Side note: Lily and James graduated in '78, and Bill Weasley started in '82. So there's not much of a gap there. Charlie Weasley and Tonks were also in that same generational cohort (Tonks and Charlie entering the same year).

Charlie never married, perhaps being a candidate for Ple's short list of Neurotypical Asexuals. He was also an exceptional seeker on the Quidditch team.

The only Quidditch players we know that went pro, though, were Krum, Wood and Ginny (who played briefly for the Hollyhead Harpies before becoming a journalist).

Tangentially related: Dun dun dun...