Despite the presence of an origin tale, this was not the first appearance of Wonder Woman, but probably around the eighth. It's somewhat hard to nail down, because this series was a prime example of Wartime paper-rationing in action. Most comics during the early forties were relegated to quarterly, and not monthly, issues. For this reason, it is presumed that this issue comes after Sensation #6 in terms of when it hit the newsstands.More importantly, though, this is the issue that makes history for Wonder Woman. It gives her the claim to "first female superhero with her own, self-titled publication".
Synopsis: Ares is again on the warpath. To counter him, Aphrodite brings forth an army of women, called Amazons. To their leader, Hippolyte, she gives a magic girdle of invincibility. The girdle proves effective against even Hercules, Ares' agent. Though he attempts to steal the girdle through guile, Hippolyte outwits the strongman, defeats Ares, and takes her Amazons to settle in peace at a place called "Paradise Island".
Hippolyte, now styled, "Queen of the Amazons" desires a family. Having been burned badly by Ares and his world of men, she chooses to procreate through non traditional means. Sculpting a figure from clay, she animates it with life and calls her creation, "Diana, Princess of the Amazons".
For an indeterminate, but presumably long, period of time, Hippolyte and her daughter live in the peace Aphrodite intended for them. Then, one day, a man crashes his plane into the island. The man is discovered to be Steve Trevor, a member of the United States Army.
Needing to rid her island of the threat of man, Hippolyte holds a competition to decide which of her Amazon warriors will once again don the magic girdle and return Trevor to the world of men. Diana, knowing nothing of the war with Ares, has fallen in love with Trevor and is therefore eager to be the one to explore Steve's world.
Her mother, though, expressly forbids it. Diana disguises herself, enters the competition, and, with seeming ease, wins the right to accompany Steve home. Knowing that departure from the island means sacrificing the immortality of paradise, Hippolyta tearfully hands over the girdle, a magic lasso that can compel those in its circle to tell the truth, and the rest of the traditional Wonder Woman outfit, to her daughter.
Diana departs in an invisible plane for Washington.
Notes: Wonder Woman's Golden Age origin is, like with all things about the character, complicated.
In its most basic form, it is a two-part tale, with one part bringing Steve Trevor to Paradise Island, and the subsequent games held to determine who will take him back. The second part is the story of how Diana actually transports him back to Washington, and her initial encounter with the "world of men". The second part is fairly straightforward, and appears in the pages of Sensation Comics #1.
However, the first bit is complicated by the fact that it appeared twice (owing to the fact that Wonder Woman effectively had two solo titles in the Golden Age), and that the second printing differed in some substantive ways from the first printing.
This is that second printing.
It is, on its face, merely an amplification of what's found in the pages of All-Star Comics #8. To add to the confusion is the fact that the story in All-Star was directly concluded in the pages of Sensation Comics, and that several issues of Sensation followed on using the continuity begun in All-Star. By the time that DC printed this expanded version of part 1, enough stories had been told in Sensation that there was a fledgling continuity in place. Thus, an "expanded" version of the All-Star story was almost certain to conflict with what had been going on in Sensation.
And it did.
Some new facts were introduced here, which contradicted what had been developing in Sensation through the original All-Star story. Here, for instance, Diana is revealed to have been made from clay by her mother. She is given the golden lasso before leaving Paradise Island here, whereas in the storyline derived from Sensation #1, she didn't get the lasso until coming back to Paradise Island in Sensation #6.
Steve Trevor's character was similarly affected by this early "dual track" publication history. According to the Sensation side of the story, he wasn't promoted to Major until issue #6. Here, he gets the promotion almost immediately upon returning from Paradise Island under Diana's care.
Perhaps because Wonder Woman was the title that survived until Crisis on Infinite Earths, though, it is this version of the story that took precedence amongst those keeping an eye on the canon. Many of the aspects of the post-Crisis, George Pérez Diana come much more directly from this story than they do the All-Star/Sensation line.
Only part one of the two-part origin tale was retold in the pages of Wonder Woman. Readers must go to Sensation #1 to see how the story concludes. Thus, ironically, Sensation is the home of both continuity and discontinuity for this version of the story.