I've never ready ANY Crisis book. None. Maybe if I'd hurry up and read Crisis on infinite Earths, it would change how I feel. But I've waited 20 odd years, what's the rush now?
To put it more accurately, the multiverse just never appealed
to me for the reasons mentioned in my previous post.
In the mid 50's, DC introduced a new Flash, different from the Flash that had been seen in the 40s. Everything was fine until the stories started connecting the two. Barry read about Jay in comic books. yes, that was established somewhere. Then the two met. A vibrational barrier separated the two worlds. The early 60's JLA met the 40's JSA. And then they got together to fight the Crime Syndicate of Earth 3.
Crisis on Infinite Earths - simplified the whole playing field. Whn it was over, one Earth, one Universe, one History. The JSA formed before the JLA. The JSA had stopped fighting at one point to explain why comics of them were not printed in the early 50s. Things that could not fit, like the Crime Syndicate were just gone. Barry, the symbol for the Multiverse, died along with the concept. And a few characters which no longer made sense simply went away.
Actually, it was established that Barry read about Jay back in Showcase #4, his first appearance. I think it was on the very first page!
Pretty good explanation of the Crisis. Unfortunately, DC mucked it up almost immediately by creating new continuities for Superman and Batman that were not set up by the Crisis. Basically, the Earth-1 Superman and Batman just ceased to exist with no in-continuity explanation. That really messed up the Legion's continuity, for example, and made every story with the original Jason Todd's continuity suspect.