1960s: "A Place in the World"
All-Star Comics vol 1 #27, by Gardner Fox and Martin Naydel
Okay, so: the Justice League didn't exist in the 1940s. Their Golden Age predecessors were the Justice Society, the first superhero team in comics and, since the characters belonged to various publishing entities who had not yet consolidated into DC Comics, technically the first inter-company crossover. The Justice Society were the headliners of All-Star Comics and featured many of comics' most popular characters — as long as they didn't have their own solo feature elsewhere. Those who headlined their own books—e.g., Superman and Batman, and later Green Lantern and Flash — were relegated to being honorary members, or, in Wonder Woman's case, team secretary.
The selection here is notable for its fervent advocacy of the disabled, as the Justice Society teams up with six disabled young men who help the superheroes solve a series of mysteries. The story shows how the young men, despite their apparent handicaps, have valuable skills and knowledge that they can use to succeed in the workplace and contribute to society. The stories' message of the need of the disabled for jobs and societal acceptance is one that is still important seventy-five years later.
The Golden Age adventures of the Justice Society can be found in the All Star Comics Archives.
(I know there are a lot of JSA fans who are already mad that the JSA is only getting one decade in the spotlight here. But rest assured they will pop up again on this list, and, you know, maybe they'll get their own list later.)
Best of the rest: “The First Meeting of the Justice Society of America” (All-Star Comics vol 1 #3), “Five Hundred Years Into the Future With the Justice Society of America” (All-Star Comics vol 1 #10), “Shanghaied Into Space” (All-Star Comics vol 1 #13), “This Is Our Enemy” (All-Star Comics vol 1 #24), “The Man Who Knows Too Much” (All-Star Comics vol 1 #29)