“Action Comics no.1” is the Holy Grail of comic books. Released in 1938, It is the comic in which Superman made his first debut and it to this day, one of the most sought out comics of all time. But, the day it was released is left under scrutiny.
A tweet from the Superman Homepage stated that the comics debut is April 18, 1938 however it also stated that some argue it was actually May 3 of the same year. However, in an article on the Comic Book Resources, writer Brian Cronin revealed that the April 18 date appears to be false. He also referenced a tweet from a reader name ‘Jesse F.’ that substantiates this claim,

“Don’t know if this is Legends-worthy, but I saw a lot of talk on Wednesday of April 18 being the actual day of Action no. 1’s release 80 years ago and I don’t think I believe that. I may be misinformed, but I’d heard the exact date of release was lost, just a range of a few weeks. Also, the exact date just happens to fall on a Wednesday? I mean, I’m sure it’s in the ballpark, but is it really the exact day?”
Cronin noted that the exact sales dates tend to be lost in history. He referenced a 1939 lawsuit that DC Comics (then National Allied Publications) had against Fox Publications. During the lawsuit, DC Comics publisher Jack Leibowitz revealed Action Comics no. 1’s release being April 18.
“I can explain that first issue. We put that out April 18 and we left it on sale for about 6 weeks. The next on-sale date was about May 25, and thereafter it was published about that time so there was only a month’s difference after that time,” recalled Leibowitz.
According to the Wonder World Comics website, National claimed that Fox Publications committed copyright infringement of the Superman character when they created their own hero Wonder Man in 1939. Motivated by the financial success of Superman and Batman, Victor Fox, an accountant for DC Comics, created Fox Publications and hired Will Eisner (Known for The Spirit) to create Wonder Man. At the time, Eisner did not suspect that this would be illegal.
Cronin told the reader that he initially believed Leibowitz since he stated the exact date. However, the thought of the release date never escaped his mind and it prompted him to research on where Leibowitz got thE April 18 date from National’s records which were reported to the Library of Congress. Furthermore, Cronin wrote that the records were for copyright dates not the sales date. National would report that on-sales date decades later. Cronin also noted that while some copies of Action Comics no.1 were hand-dated around April, it was for the records of the stores that received them; not sold them.
Cronin brings up a theory by Mike Violes of Mike’s Amazing World which states that the comic (as mentioned by the Superman Homepage tweet) was likely sold on May 3, 1938 due to comics being sold on Tuesdays at the time. Cronin even stated that although Mike might be wrong, it can be agreed that the comic was not sold on April 18, 1938.
The on-sales date of Action Comics’ No. 1 has to be one of the mysteries under scrutiny next to the debate on whether Marvel Icon Stan Lee or artist Jack Kirby created the Fantastic Four and other Marvel characters. It is another part of the controversy surrounding the comic which was bought by National from Joe Shuster and Jerry Siegel for $150.