1st appearance of the Golden Age Flash in the Silver Age
Key issue of the Mutliverse concept
2nd appearance of The Shade
First mention of Earth-2, home of the Golden Age superheroes
[March 2022 - rumor that Warner Bros. will incorporate a Crisis on Infinite Earths event (which was already adapted for TV) in The Flash movie in an effort to streamline their universe of live-action projects. If this is the scenario, a Multiverse concept will first have to be established as it did in this issue]
