The cover image is well-known, in part, because it was the magazine's inaugural issue, but it also happened to harbor a call to return the character her superheroic status, after having been de-powered for a few years. Writer Denny O'Neil has since apologized profusely and repeatedly for not fully understanding what the character meant to so many women. Steinem and Ms. effectively brought Wonder Woman some broad media attention, and essentially got her powers reinstated and put Lynda Carter in Wonder Woman's costume on television.
I was trying to do some research on this after I learned of the impending magazine anniversary, but I haven't actually been able to read the contents of that iconic magazine. I kept finding references to it but, oddly, there doesn't seem to be much in the way of page scans or torrents or anything. I found one poor scan of the first page of Joanne Edgar's "Wonder Woman Revisited" article, but I gather the real meat of the piece is after that. I also understand Ms. republished several pages of Wonder Woman's origin story, but I don't know which version or how well it was reprinted either. I'm sure I could track down an actual copy of the magazine given time, but I only had the anniversary pointed out to me on Facebook last night.
For a long time, Wonder Woman was in perpetual publication for legal reasons. Kurt Busiek noted in 2005:
... as I understand it, the terms were that DC had to publish at least four issues with "Wonder Woman" as the banner lead feature or rights would revert [to the Marston Estate]. That's why DC did the LEGEND OF WONDER WOMAN mini-series that I wrote and Trina Robbins drew — the Perez revamp was in development, but coming along slowly, and they had to publish something to fulfil the contract terms.This was backed up by Wonder Woman über-fan Andy Mangles, who also confirmed (as much as he's able to) that the stipulations of the original contract and subsequent purchase include a non-disclosure clause, meaning that no one who's actually seen the paperwork is legally allowed to talk about it.
They specifically didn't want something that would be attention-getting, because they didn't want to undercut the revamp. So they wanted something gentle and nostalgic, and we had fun doing it.
In the intervening years, though, I'm given to understand that at some point DC bought the character outright, and thus those contract terms are no longer in force.
What that means is: William Moulton Marston, by generating a very specific, very deliberate contract with DC, singled-handedly kept Wonder Woman in publication and in the public consciousness in some form for at least 45 years. (From her debut in in 1942 until the 1987 Perez book Busiek noted.)
Marston's personal life tends to color history's view of him (which is why, I suspect, there isn't a printed biography of the man available -- somebody please get on that!) but it was basically Marston and his lawyer that kept Wonder Woman around long enough to become the icon she is. Odds are that, without the continual publication stipulation, Wonder Woman would've vanished from the newsstands in the 1950s, perhaps only seeing a modest revival as an Earth-2 inhabitant alongside Jay Garrick and Alan Scott. She might not have had the de-powering stories to contend with, but she would've faced a much bigger enemy: obscurity. And if that were the case, who would've graced the cover of Ms. #1? Rosie the Riveter?
Marston is remembered for creating a great character in Wonder Woman, but perhaps equally significant is that he created the means by which this great character would get continued exposure long enough to become ingrained in the public consciousness. Marston didn't actually create an icon, but he set Wonder Woman up to ensure that she would become one.