The early 1960s gave birth to the most exciting era comic book fans would ever know, due for the most part to the efforts of DC Comics editor Julius Schwartz. Beginning in the mid-40s, this one-time science-fiction literary agent (and acknowledged co-founded of science-fiction fandom some fifteen years earlier) began shaping the adventures of some of DC's greatest heroes, including the Justice Society of America. He survived the late 1940s decline of the superhero by editing some of the most innovative genre books of the day to play a key role in the superhero revival with the 1954 "recreation" of the Golden Age hero The Flash. Several years and many heroic revivals later, Schwartz brought forth the modern equivalent of the Justice Society, the Justice League of America. Under Schwartz's direction, with its innovative interactions between the JLA members and incredible, high-concept science-fiction storylines by writer Gardner Fox, the Justice League of America was one of the most exciting comics of the time.. and became a groundbreaking title with JLA 21-22. The two-part "Crisis on Earth-One" and "Crisis on Earth-Two" furthered the link—first forged in an earlier Schwartz-edited title, The Flash—between the Golden Age superheroes remembered and much beloved by older fans and the modern day heroic counterparts with a concept that became known as "multiple-Earths." Fans both old and young went wild for these stories (which went on to become an annual event in JLA for almost the next two decades), and the Justice League of America stories reprinted in this volume made comics history.