1. The Bandit Robots of MetropolisSuperman Sunday Newspaper Strip - October 27, 1940 to December 15, 1940
As far as “Iconic Superman Stories” go, you can’t get much better than “The first time Superman fought an army of robots”.
Titanic mechanical men perform destructive raids upon Metropolis and only Superman stands in their way. When Lois is inevitably abducted by the masterless robot menaces, the Man of Steel follows them to their lair to destroy them once and for all.
It’s worth mentioning that the inspiration for this story is usually credited to Norvell W.Page, the author of the lion’s share of pulp hero The Spider’s adventures. In this case, the shadowy hero met robotic giants in a tale with the typically understated title of “Satan’s Murder Machines” (Reprinted in more mellow times as as “Robot Titans of Gotham” and “The Iron Man War”).

    The Bandit Robots of Metropolis
    Superman Sunday Newspaper Strip - October 27, 1940 to December 15, 1940

    As far as “Iconic Superman Stories” go, you can’t get much better than “The first time Superman fought an army of robots”.

    Titanic mechanical men perform destructive raids upon Metropolis and only Superman stands in their way. When Lois is inevitably abducted by the masterless robot menaces, the Man of Steel follows them to their lair to destroy them once and for all.

    It’s worth mentioning that the inspiration for this story is usually credited to Norvell W.Page, the author of the lion’s share of pulp hero The Spider’s adventures. In this case, the shadowy hero met robotic giants in a tale with the typically understated title of “Satan’s Murder Machines” (Reprinted in more mellow times as as “Robot Titans of Gotham” and “The Iron Man War”).

  2. The Dangerous InheritanceSuperman Sunday Newspaper Strip - July 28, 1940 to October 20, 1940
 
Lois Lane’s extended family continues to be a source of adventure for Superman. This time around, an uncle has left Lois an enormous tract of untamed wildnerness – land which certain shady types are willing to kill to get their hands on.
It will be several years before Superman’s family – his relatives from Krypton, primarily, but also the extended Kent clan of Earth – begins to make its presence known in the comics. For this to happen, before his cousin can pop out of a spaceship or evil uncle can step out of the Phantom Zone, Superman’s actual history needs to be laid down.
At present, Superman is a living being who only exists in the moment – his world of birth only exists to explain his powers, his adoptive parents only exist to give him his mission against crime. Before his own history can begin to influence the character, he has to gain a history…

    The Dangerous Inheritance
    Superman Sunday Newspaper Strip - July 28, 1940 to October 20, 1940

     

    Lois Lane’s extended family continues to be a source of adventure for Superman. This time around, an uncle has left Lois an enormous tract of untamed wildnerness – land which certain shady types are willing to kill to get their hands on.

    It will be several years before Superman’s family – his relatives from Krypton, primarily, but also the extended Kent clan of Earth – begins to make its presence known in the comics. For this to happen, before his cousin can pop out of a spaceship or evil uncle can step out of the Phantom Zone, Superman’s actual history needs to be laid down.

    At present, Superman is a living being who only exists in the moment – his world of birth only exists to explain his powers, his adoptive parents only exist to give him his mission against crime. Before his own history can begin to influence the character, he has to gain a history…

  3. Episode 5: The ChosenStrips 31-38 (June 2, 1940 to July 21, 1940)
Prominent Metropolitan business leaders have turned ruthless in their feverish quest to acquire greater wealth - and Superman discovers that a shadowy secret society is behind it all. Held in the thrall of the mysterious figure known only as “The Lamite”, the great men of industry find themselves all but enslaved to the wishes of their mysterious master. It falls on the Man of Steel to uncover The Lamite’s lair and release his terrible grip upon his subordinates.
Ultimately, The Lamite’s lair is uncovered and the mastermind of the conspiracy is revealed to be yet another cunning mad scientist. Moreover, it turns out that The Lamite controls an army of mutant animals (of which Superman still handily disposes), and subsequently dies in a collapsing castle.
Oddly, the revelation of The Lamite’s identity, his monster pets and his prompt dispatch from the mortal realms all happen in a single episode, after a fairly long-winding and not-at-all-mad-sciencey series of Sunday episodes. More than likely it was an editorial decision to cut the storyline short - the daily newspaper strips were running a similar storyline, and regular readers might’ve had trouble distinguishing between the plot point. 
It’s also likely that, citing the cost and high visibility of the Sunday strips, the powers-that-be demnaded more science fiction spectacle for the color funnies, thus The Lamite turning out to be another member of the Mad Science fraternity…

    Episode 5: The Chosen
    Strips 31-38 (June 2, 1940 to July 21, 1940)

    Prominent Metropolitan business leaders have turned ruthless in their feverish quest to acquire greater wealth - and Superman discovers that a shadowy secret society is behind it all. Held in the thrall of the mysterious figure known only as “The Lamite”, the great men of industry find themselves all but enslaved to the wishes of their mysterious master. It falls on the Man of Steel to uncover The Lamite’s lair and release his terrible grip upon his subordinates.

    Ultimately, The Lamite’s lair is uncovered and the mastermind of the conspiracy is revealed to be yet another cunning mad scientist. Moreover, it turns out that The Lamite controls an army of mutant animals (of which Superman still handily disposes), and subsequently dies in a collapsing castle.

    Oddly, the revelation of The Lamite’s identity, his monster pets and his prompt dispatch from the mortal realms all happen in a single episode, after a fairly long-winding and not-at-all-mad-sciencey series of Sunday episodes. More than likely it was an editorial decision to cut the storyline short - the daily newspaper strips were running a similar storyline, and regular readers might’ve had trouble distinguishing between the plot point. 

    It’s also likely that, citing the cost and high visibility of the Sunday strips, the powers-that-be demnaded more science fiction spectacle for the color funnies, thus The Lamite turning out to be another member of the Mad Science fraternity…

  4. Giants of Doom ValleySuperman Sunday Newspaper Strip - February 11, 1940 to March 3, 1940
It’s 1940 and Superman has gone full-fledged science-fiction. Ultra had his death rays and Dr.Grout his hypnosis, but the Giants of Doom Valley includes hemophiliac titans and bullet-shaped driving vessels. This short adventure sets the tone for the color Sunday strips, competing as they are with the fantastic adventures of Flash Gordon and Buck Rogers. Moving forward, Superman increasingly meets space-fiends and science-monsters in his adventures…

    Giants of Doom Valley
    Superman Sunday Newspaper Strip - February 11, 1940 to March 3, 1940

    It’s 1940 and Superman has gone full-fledged science-fiction. Ultra had his death rays and Dr.Grout his hypnosis, but the Giants of Doom Valley includes hemophiliac titans and bullet-shaped driving vessels. This short adventure sets the tone for the color Sunday strips, competing as they are with the fantastic adventures of Flash Gordon and Buck Rogers. Moving forward, Superman increasingly meets space-fiends and science-monsters in his adventures…

  5. The Mindless Slaves of Dr. GroutSuperman Sunday Newspaper Strip - December 31, 1939 to February 4, 1940
Clark - and Superman - encounter their second mad scientist, the insidious Dr.Grout who hypnotizes unemployed men into becoming mindless assassins. 
As Superman makes short work of assorted thugs and ne’er-do-wells across multiple media, the cops-and-robbers elements of his stories increasingly give way to elements of science fiction. Ultra initiates the upcoming rogues gallery of mad scientists in the pages of Action, and in this arc of the color Sunday newspaper strips we’re introduced to Superman’s second evil scientific nemesis, “Dr.Grout” (A white-jacketed mesmerist who hypnotizes homeless men into becoming brainwashed assassins - some shades of “Reign of the Super Man” to be had).
Although Superman’s adventures up to this point are largely ground-level, you can at least say in his defense that he’s yet to repeat a theme - he’s put the boot to one wife-beater, one lynch mob, one war profiteer, one overzealous warden, one cruel orphanmaster, and so on. It’s one beating per offense in Superman’s world! 
But, of course, avoiding repetition among the violators of the social trust against whom Superman pits his tremendous strength means that the Man of Steel, in short order, will eventually find himself battling reckless drivers and pinball machine syndicates. Ultimately, labors which test his tremendous powers (and which, in turn, encourage the invention of new powers) become the order of the day, and a small army of mad scientists will lead Superman’s march into science fiction territory…

    The Mindless Slaves of Dr. Grout
    Superman Sunday Newspaper Strip - December 31, 1939 to February 4, 1940

    Clark - and Superman - encounter their second mad scientist, the insidious Dr.Grout who hypnotizes unemployed men into becoming mindless assassins. 

    As Superman makes short work of assorted thugs and ne’er-do-wells across multiple media, the cops-and-robbers elements of his stories increasingly give way to elements of science fiction. Ultra initiates the upcoming rogues gallery of mad scientists in the pages of Action, and in this arc of the color Sunday newspaper strips we’re introduced to Superman’s second evil scientific nemesis, “Dr.Grout” (A white-jacketed mesmerist who hypnotizes homeless men into becoming brainwashed assassins - some shades of “Reign of the Super Man” to be had).

    Although Superman’s adventures up to this point are largely ground-level, you can at least say in his defense that he’s yet to repeat a theme - he’s put the boot to one wife-beater, one lynch mob, one war profiteer, one overzealous warden, one cruel orphanmaster, and so on. It’s one beating per offense in Superman’s world! 

    But, of course, avoiding repetition among the violators of the social trust against whom Superman pits his tremendous strength means that the Man of Steel, in short order, will eventually find himself battling reckless drivers and pinball machine syndicates. Ultimately, labors which test his tremendous powers (and which, in turn, encourage the invention of new powers) become the order of the day, and a small army of mad scientists will lead Superman’s march into science fiction territory…

  6. “Twenty-Four Hours to Run”Superman Sunday Newspaper Strip - November 5, 1939 to December 24, 1939
Having already broken the daily newspaper strip barrier, Superman’s next skyscraper-busting single-bound is into the four-color world of the weekly Sunday strip.
Running a distinct storyline from the six-a-week daily newspaper strip, the Sunday strip bore its own continuity from week-to-week, meaning that while a single plot in the dailies might wrap up in two or three weeks, the Sunday strips would run an arc over the course of several months. This debut story - wherein Superman must protect logger Mike Hensley from his rival’s repeated attempts on his life - runs from the first week of November 1939 through Christmas Eve.
The story abounds with the classic Siegel and Shuster energy of the early strips, written and drawn as it is by the original creators. The workload, however, has officially reached a tipping point and both strips would begin to boast a parade of luminaries working as ghosts to Superman’s original artist.
Paul Cassidy is the first to take up the reins, providing inks and detail work on early strips. Throughout the Forties, a multitude of other artists from Leo Nowak to Jack (Starman) Burnley to, of course, Wayne Boring and Stan Kaye would provide the artwork. 
Tireless Jerry Siegel remains the writer of the strips until drafted in 1943, continuing to forge his singular - if evolving - vision of the Man of Tomorrow.

    “Twenty-Four Hours to Run”
    Superman Sunday Newspaper Strip - November 5, 1939 to December 24, 1939

    Having already broken the daily newspaper strip barrier, Superman’s next skyscraper-busting single-bound is into the four-color world of the weekly Sunday strip.

    Running a distinct storyline from the six-a-week daily newspaper strip, the Sunday strip bore its own continuity from week-to-week, meaning that while a single plot in the dailies might wrap up in two or three weeks, the Sunday strips would run an arc over the course of several months. This debut story - wherein Superman must protect logger Mike Hensley from his rival’s repeated attempts on his life - runs from the first week of November 1939 through Christmas Eve.

    The story abounds with the classic Siegel and Shuster energy of the early strips, written and drawn as it is by the original creators. The workload, however, has officially reached a tipping point and both strips would begin to boast a parade of luminaries working as ghosts to Superman’s original artist.

    Paul Cassidy is the first to take up the reins, providing inks and detail work on early strips. Throughout the Forties, a multitude of other artists from Leo Nowak to Jack (Starman) Burnley to, of course, Wayne Boring and Stan Kaye would provide the artwork. 

    Tireless Jerry Siegel remains the writer of the strips until drafted in 1943, continuing to forge his singular - if evolving - vision of the Man of Tomorrow.