I first learned of him when he was on JLA. Then I found out that he had been instrumental in the re-creation of Silver Age classics like The Flash (Barry Allen), Green Lantern (Hal Jordan), the Atom (Ray Palmer), and Hawkman (Katar Hol). By the time I was branching out and buying things besides JLA he was still on The Flash and was also doing Superman and Action Comics. By the time of the Superman movies, he was in charge of all of the Superman-related titles.
Unfortunately, he never handled the Legion of Super-Heroes or Aquaman. I think that both of these series would have been better and, in the case of Aquaman, lasted longer, if he had been involved.
Julius Schwartz was born on June 19, 1915. He passed away on February 8, 2004.
Happy Birthday, Julius Schwartz!
from FLASH 179, where Schwartz meets the Flash
from JLA 123, where writers Cary Bates and Elliot S. Maggin
meet the Justice League & Justice Society
from the Julius Schwartz-dedicated JUSTICE LEAGUE comic from 2004
art by Joe Giella