In 1950 DC Comics, having had a pretty good run so far with Superman, Batman, Green Arrow, and the like, seemed to be expanding its lineup, heading out into areas other than superheroes because they were becoming almost passé. Naturally, leaving such powerhouses behind would be foolish but not looking into other areas would also not be good business.
So numerous non-powered characters would get their chance to shine. One of the titles was Danger Trail and in its pages would be several different tales of adventure and, well, danger. The magazine lasted only 5 issues before disappearing and in those 5 issues, only one repeat character was depicted. King Faraday was there for the 1st through 4th issue with an exciting and long considering it was an anthology magazine. Faraday did not make it into the 5th issue and the magazine did not make it past that.
Apparently there had been a 5th Faraday story, however, because just a couple years after Danger Trail came and went, that tale showed up as a back item in the very popular World's Finest Comics. That magazine had been a place for new stories about Superman and about Batman and Robin and would some time later become the place where Superman and Batman worked together. There were often back stories to fill the pages in each of the issues and in #64, the story was the last solo adventure of Faraday.
Jump ahead a decade and in the showcase magazine cleverly called Showcase, a magazine devoted to giving new characters or secondary characters a chance to shine. In two consequtive issues, four of the previously told tales were reprinted. And then the spotlight moved on to someone else and Faraday disappears again. For a while.
That while lasted another 14 years. Then in a major collection of Showcase stars for the 100th edition, apparently all or nearly all of those who had been in the previous issues showed up in one way or another for a major event in which that finicky old space/time continuum gets messed with. Faraday's part in the story was small but at least he was asked.
Having been asked, though, was enough to get him noticed, if not by the readers enough to demand a full-time return, at least enough by the writers who, in need of a government agent to growl and snarl and threaten and cadjole super-heroes into doing things, thought of King Faraday and said, 'why not?'
From that point on, King Faraday, who had never really had a definitive job, gets a good number of them. His employer changes from time to time, unless he was misrepresenting who he answered to or, more likely, the superheroes who are usually quick to react and slow to think about it just got it wrong.
For whatever reason, Faraday would become a common reappearing thorn in many a side of a powered person. He especially annoyed Dick Grayson who dealt with him over the years as Robin, Nightwing, and just Grayson. They seldom had nice things to say about each other but that made the relationship fun.
Also fun at times was the rivalry between Faraday and a resurgent who, like Faraday, was brought back to be the voice of the cloak and dagger world whenever it intruded into superhero work or vice versa.
Faraday would be given one more, as of this writing, solo adventure in 1993 when a very nasty fellow called Kobra tries to create a weapon of mass destruction to use for very nasty business. It was a pretty intense fight between them and lasted 4 issues.
After that, Faraday returned to the sidelines, popping up once in a while for this reason or that but in a larger role with the new intelligence organization, Checkmate, which would find itself mixed up in just about everybody's business in the whole DC universe. Faraday was certainly not present in all those times but enough to make sure virtually everyone who wore a cape or spandex knew his name. Most of them without pleasure.
I have listed a good number of the magazines that that Faraday has been in. There are more that follow the ones I have listed and possibly one or two I missed before then. My information is from a fantastic site: Unofficial Guide to the DC Universe. What a treasure trove of info that site is.
If I made any mistakes, though, it is my fault and not theirs.