As mentioned in my last post, 1970 was Mort Weisinger's last year editing the Superman line of comics. After he retired, DC distributed the Superman line among the remaining editors and gave one - Jimmy Olsen - to new comer Jack Kirby.
I don't know if they split up the responsibilities because the rest of the staff were too close to capacity for any one editor to pick up all the books, or if publisher Carmine Infantino considered it an experiment to see which editor did the best job with the character.
In the silver age there really weren't such things as the "reboots" that became so common in the eighties, nineties and the aught-naughts. New editors simply took over books and took them in new directions. Continuity wasn't wiped out; at most it was ignored. The page below followed the one above and explained what DC planned to do with each Superman Family book while pointing out that this wasn't the first change for Superman; he had evolved over the years since his introduction.The Superman comic was given to Julius Schwartz, who put Denny O'Neil on it and introduced Marvel style multi-issue subplots to the book. The series began with a literal bang, an explosion at a Kryptonite reactor that rendered all Kryptonite on Earth inert and harmless. It was a major change to the character, removing an overused plot device from future consideration for many years. The first issue also introduced a byproduct of the explosion, a kind of Superman doppelganger made of the sand Superman landed in during the explosion. Whenever the sand creature roamed near Superman, he sapped some of Superman's powers. Eventually the subplot led to a final confrontation. The sand creature permanently took half of Superman's powers and left earth, leaving a less powerful, more write-able super-character.
Action Comics was given to Murray Boltinoff, who put Clark Kent on television and sent him out on the road like Charles Korault on the CBS news during this same era, hunting out stories and finding Super-adventures.
Superboy had previously been given to Murray Boltinoff as well. Early in Murray's run on Superboy he de-aged Ma and Pa Kent.
Jimmy Olsen went to Kirby, who quickly sent Jimmy and Superman into a series of adventures as creative as Kirby's best Fantastic Four stories from issue 40 to 60. He introduced the Hairies, the Project, the Guardian and Newsboy Legion, Dubblex, and skirted around the stories he told in his Fourth World books.
Lois Lane became E. Nelson Bridwell's book. ENB ended the long time rivalry between Lois and Lana Lang by abruptly sending Lana off to Europe. The stories in the Lois Lane book became relevant to the times. Lois wrote stories about racial prejudice. Lois became more adult in other ways as well. She no longer connived to trick Superman into revealing his secret identity or marrying her. To the back of the book he introduced Rose and the Thorn, a hip booted split personality heroine seeking revenge for the death of her father at the hands of the criminal organization "the 100". The series was a kind of count down as she eliminated the members of the 100 one-by-one and the comic kept score.
Adventure Comics was given to Mike Sekowsky. Mike started his tenure with a cover featuring new designs for Supergirl's costume. He chose one with a mini-skirt, hip boots and gloves. Then he introduced a mysterious malady that suddenly took away Supergirl's powers at inopportune moments and challenged her in a manner similar to his contemporaneous treatment of Wonder Woman. He also introduced a new villainess, Luthor's cousin, Nasthalthia.
Finally, World's Finest went to Julius Schwartz as well. Julie threw Batman out of the book and turned it into Superman's version of a Brave and Bold comic, teaming Superman up with a different character each month, usually characters he was known for editing.
After a few years the books were shuffled again. Action went to Julie. Adventure to Joe Orlando. Lois to a romance comic editor, and World's Finest to Murray, who brought back Batman as Superman's regular partner. But that's a different blog...