The first super-hero team to appear in comics was the Justice Society of America in All-Star Comics #3 in 1940. The story has been reprinted in Famous First Edition #F-7 (1974), in Millennium Edition: All-Star Comics #3 (2000), and in All-Star Comics Archives vol. 1. The story is also available digitally from comixology.com. for 1.99.
The story tells of the JSA's first meeting at a hotel conference room where the heroes meet for dinner and swap stories of solo adventures. So we don't get to see a team-up per say this issue.
The story is dated in that there are fewer attempts than today to inject any dose of realism into the story. But then this is back when in-house ads were addressed to "boys and girls." We find the JSA having the hotel to themselves since Sandman has put all the guests to sleep. Never mind that some guests might have had to catch a flight, or report to a work conference, or meet a sick relative. But we weren't supposed to think of all that back then. Other juvenile aspects of the story includes a shark who thinks in English referring to Flash as a "nice juicy man."
The 1940s slang is also amusing. Flash addresses the shark as "old kid." His costume is described as a "screwy outfit." Strange happenings are said to be "mighty queer." A woman's curiosity is stereotypically referred to as being "just like a woman." A ship's captain is described as being "happy as a kid" and Hawkman lands a successful punch exclaiming, "What a lulu. Right on the button." The Atom says both, "Holy Smoke" and "Swell."
Most of the scripts are by Gardner Fox with pencils contributed by Everett E. Hibbard. A brief comedic interlude is scripted and drawn by Sheldon Mayer in which the original Red Tornado crashes the party. The Spectre story is co-scripted by Jerry Siegel of Superman fame. The most outstanding art is that of Sheldon Moldoff for the Hawkman story. It has a pulp sci-fi feel to it that isn't quite as cartoony as the rest of the book. The panel with Hawkman appearing at Shiera Sander's bedside borders on a very subdued eroticism.
A stand-out feature of the book is that most heroes of the time had a leading lady, but not always a damsel in distress. For the Flash it was Joan Williams, his girlfriend who in later comics becomes his wife. Shiera Sanders is likewise destined to marry Hawkman. Rex Tyler (Hour-Man) is found working at Bannerman Chemicals where his leading lady is boss's niece Regina Paige. While Regina made several appearances in Hour-Man's early adventures, it is Wendi Harris who becomes his wife, appearing first in Showcase #56 (1965). Sandman pals around with Dian Belmont, a socialite and amateur detective. They had an ongoing relationship in the comics well into their golden years, but never officially marry. Green Lantern's leading lady, Irene, appears in only a couple of panels. College Sophomore Al Pratt's crush, Mary James is none too impressive. It's another one of those romantic tension situations in which the lady idolizes the hero (the Atom) but is not impressed by the man behind the mask. Dr. Fate's interest is Inza Cramer, who later becomes his wife. Only the Spectre lacks a leading lady in his story.
While written for kids the stories are entertaining enough, with some having an almost creepy element due to occultism or science gone awry. The stories cover a wide variety. Flash, the Atom, and Hour-Man are more typical super-heroics while Hawkman, Sandman, Dr. Fate, and the Spectre are more of the pulp fiction, macabre, fantasy, or noir categories. Overall, it's a great book concluding with a summons by the F.B.I. chief for the JSA to meet him in Washington which occurs in issue 4.