I’m mostly looking for stories on the original founding of the first ever roster, and I’m guessing there are multiple versions of that.
If there are good team reformation stories or stories about the foundation of a new iteration or subteam, I’m open to those recommendations too.
Oddly enough, there's currently only one origin story for the JSA* (modified for pre and post Crisis). It's ably recounted here, and has been published here and here.
As near as I can tell, it hasn't been re-written... yet.
* "Origin" meaning their first team-up. In All-Star Comics #3 they met in their headquarters for the first time, seemingly for no particular reason.
Yeah, there's only really been one origin story, that was written decades after their first apperance, in the 70's. It was retconned after COIE to account for Superman and Batman being erased from JSA history, but remained largely unchanged IIRC.
If we're going beyond the original/classic team, I actually love James Robinson's Earth 2 - the first arc is a great take on the origins of the New Earth 2 JSA, and kinda inspired the JL movie as well.
last year's DCAU "reboot" began with an animated re-telling of the origin story, tying it together with the "Flash of Two Worlds" story...
Barry universe-hops, meets the JSA (condensed line-up of Wonder Woman - as the leader, Hawkman, Black Canary, Flash, Dr Fate and, later, a reluctant Golden-Age Superman), gets inspired by them, goes back home, meets his Superman and suggests forming a "League"
DC Special #29. (1977)
A wonderful Levitz penned story illustrated by Staton & Layton all wrapped in a beautiful Neal Adams cover.
"My name is Wally West. I'm the fastest man alive!"
I'll try being nicer if you try being smarter.
Currently(or soon to be) Reading: Alan Scott: Green Lantern, Batman/Superman: World's Finest, Fire & Ice: Welcome to Smallville, Green Arrow, Green Lantern, Jay Garrick: The Flash, Justice Society of America, Power Girl, Superman, Shazam, Titans, Wesley Dodds: Sandman, Wonder Woman, & World's Finest: Teen Titans.