COMIC LEGEND: Walter Simonson and Chris Claremont invented the Source Wall during their Uncanny X-Men/New Teen Titans crossover.
STATUS: Basically True
In the DC Universe, the Source Wall is the end of the known universe and it contains all of the beings who tried to get past it...
Recently, in Greg Burgas' spotlight on Walter Simonson's artwork for Uncanny X-Men/New Teen Titans, commenter Chrome Aardvark noted that that 1982 crossover was the debut of the Source Wall.
Travis Pelkie wrote in to ask:
Did the Source Wall really first appear in that X-Men/Titans crossover?
The answer is BASICALLY true.
It's literally the first appearance of the Source WALL, but the concept appeared in New Gods #5...
but yes, not until that 1982 crossover did the Source Wall actually appear physically...
It fit so well that it has been an accepted part of New Gods history ever since. Jack Kirby himself picked up on it, so that must be quite the feather in Chris Claremont and Walter Simonson's respective caps.
That must be the longest-lasting thing out of a Marvel/DC crossover ever! Unless, of course, you're the one person who loved Access.