Research can be a frustrating beast. Much of what I read about the history of comics and comic fandom focuses on obscure and largely irrelevant (to me) minutia, not to mention often being deadly dull. But every now and then, I can find a beautiful gem that makes much of the tedium worthwhile.
In reading Bill Schelly's Founders of Comic Fandom, there's a two-page biography of Steve Perrin, a prolific fanzine author and publisher before he got around to creating RuneQuest. The gem here is that Perrin created a character called The Black Phantom that debuted in Mask and Cape #4 circa 1964. That's him prominently displayed on the cover. Schelly describes the Black Phantom (and another hero that Perrin debuted that issue called The Wraith) as " the first black costumed heroes in fandom."
I read that and thought to myself, "In fandom? Doesn't the 1964 debut even pre-date Marvel's Black Panther?"
I double-checked and, indeed, the Black Panther debuted in Fantastic Four #52 by Stan Lee and Jack Kirby. Cover dated July 1966.
Now, Black Panther was certainly not the first black character to appear in comics. Lee Falk introduced Lothar into his Mandrake the Magician stories decades earlier, and Dell already held the distinction of being the first to publish a comic book (Lobo) with the headline character being African-American. But Panther is generally considered the first black superhero.
Except that, apparently, he isn't.
Perrin's story in Mask and Cape is prose, with a few illustrations. The Black Phantom didn't see a true comic book realization until Fantasy Illustrated #6, which didn't come out until late 1966, after Panther's debut. But the idea of a black superhero is at least two years earlier than Black Panther.
Let me reiterate that: The first black superhero was published TWO YEARS before Black Panther.
Lee and Kirby did NOT create the first black superhero. The first superhero to appear in a comic book? Sure. But not the first black superhero. Please update your mental database, Wikipedia, etc. accordingly.