All-American Publications is one of three American comic book companies that combined to form the modern-day DC Comics, one of the world's two largest comics publishers. Superheroes created for All-American include the original Atom, Flash, Green Lantern, Hawkman, and Wonder Woman, all in the 1940s' Golden Age of comic books.
Max Gaines, future founder of EC Comics, formed All-American Publications in 1938 after successfully seeking funding from Harry Donenfeld, CEO of both National Allied Publications (publisher of Action Comics and other titles) and sister company Detective Comics (publisher of that namesake comic book). As Gerard Jones writes of Donenfeld's investment:
While All-American, at 225 Lafayette Street in Manhattan, was physically separated from DC's office space uptown at 480 Lexington Avenue, it used the informal "DC" logo on most of its covers for distribution and marketing reasons. (The DC logo at the time was also used for National's unofficial branding, capitalizing on the success of Batman in Detective Comics.) In 1946, Gaines let Liebowitz buy him out, keeping only Picture Stories from the Bible as the foundation of his own new company, EC. "Liebowitz promptly orchestrated the merger of All-American and Detective Comics into National Comics.... Next he took charge of organizing National Comics, Independent News, and their affiliated firms into a single corporate entity, National Periodical Publications".
Before that merger, Gaines had first rebranded All-American with its own logo, beginning with books cover-dated February 1945: All-Flash #17, Sensation Comics #38, Flash Comics #62, Green Lantern #14, Funny Stuff #3, and Mutt & Jeff  #16, and the following month's All-American Comics #64 and the hyphenless All Star Comics #24. When Liebowitz later merged his and Donenfeld's companies, the All-American titles first bore the DC logo once again (starting with December 1945's Sensation #48 and Flash Comics #68, continuing with All-American #70, All-Flash #21, Comic Cavalcade #13, Green Lantern #18, Funny Stuff #7, and Mutt & Jeff #20) before finally being fully absorbed by what was now National Periodical.
During All-American's existence, much cross-promotion took place between the two editorially independent companies, so much so that the first iteration of the Justice Society of America, in All Star Comics #3 (Winter 1940/41), included in its roster the National characters Doctor Fate, Hour-Man (as it was then spelled), the Spectre, and the Sandman — creating comics' first intercompany crossover, with characters interacting, although National's Sandman, Spectre and Hour-Man had previously appeared in solo adventures in All Star Comics #1 (Summer 1940).
With Gaines as editor, assisted by Sheldon Mayer, All-American Publications launched its flagship series All-American Comics with an April 1938 premiere. Like many comics of the time, All-American debuted with a mix of newspaper comic strips, reprinted in color, and a smattering of original, comic-strip-like features. Among the strips were three huge hits of the era: Mutt and Jeff, by Al Smith ghosting for strip creator Bud Fisher; Skippy, by Percy Crosby; and Toonerville Folks by Fontaine Fox. New content included Scribbly, a semiautobiographical Mayer feature about a boy cartoonist. All-American Comics lasted 102 issues through October 1948.
Also debuting that month was Movie Comics ("A full movie show for 10 cents"), featuring simple adaptations of movies using painted movie stills, as well as cartoonist Ed Wheelan's popular Minute Movies comics. The first of its six issues through Aug. 1939 adapted no fewer than five films: Son of Frankenstein, Gunga Din, The Great Man Votes, Fisherman's Wharf, and Scouts to the Rescue.
The next two comics were Mutt & Jeff, which ran 103 issues from Summer 1939 - June 1958; and the company's superhero debut, Flash Comics #1 (Jan. 1940), which introduced the super-speedster title character, created by writer Gardner Fox and artist Harry Lampert, as well as the Golden Age Hawkman and future Hawkgirl, by Fox and artist Dennis Neville, and Johnny Thunder, by scripter John Wentworth and artist Stan Aschmeier, among other features.
The Golden Age Green Lantern, from Batman writer Bill Finger and artist Martin Nodell, debuted in All-American Comics #16 (July 1940), followed by the original Atom, created by Bill O'Connor and penciler Ben Flinton, in All-American #19 (Nov. 1940). Wonder Woman was introduced in a nine-page story in All Star Comics #8 (Jan. 1942), the product of psychologist William Moulton Marston and Max Charles Gaines (under the pseudonym Charles Moulton), and drawn by artist Harry G. Peter.
Titles begun under All-American Publications. Issues after the 1946 merger are National Periodical Publications / DC Comics.