Prior to the completion of The Lord of the Rings in 1955, the fantasy genre was made up of stories and novels from many varied sources: on the one hand, there were the stories crafted by Hans Christian Anderson, or the fairy tales we were told as children; on the other, the whimsies of James Thurber or many of the tales that made up each issue of John Campbell's Unknown magazine. The benchmark for defining this genre would seem to be that providing a story does not deal with science, is not meant to horrify, and is not based in what we would call reality, then that story would qualify as a fantasy you could expect to find prior to Tolkein.
     In The Lord of the Rings, Tolkein not only created a fantasy of epic proportions in terms of length, he also made his epic unlike any that had gone before. Elves and trolls had long been the stuff of European stories and legends, as had dragons and rings of power, but Tolkein took these ideas and fleshed them out by creating a fantasy world that was consistent within itself. The quest, that actually begins in the prequel The Hobbit, takes place in a world with a history, a form of governmental structure, and even a class structure: something that no one had attempted before and, to date, no one has surpassed.
     Unfortunately, the changes that Tolkein brought to fantasy were also the undoing of the genre. Today, you would be hard pressed to find much, if any, fantasy that does not deal with dwarves, elves, swords, or rings. Quests seem to be the order of the day and most all of them are "borrowed", sometimes only very thinly disguised, from Tolkein.
     The covers displayed above are of the first American printing issued in 1965 and displayed here as they were designed:  to be viewed as one large painting (I vaguely remember seeing a poster offered of this tryptich design at one time). You will also notice a small red box on each cover. This box proclaims these books as being the "authorized" editions. Why? Glad you asked.
     Ace books attempted to get the rights to The Lord of the Rings for US publication in the early 60s. After not receiving an answer from the publisher, or just going ahead on the grounds that the copyright from England was not valid (stories vary), Ace published the trilogy without Tolkein's consent. How long the books were on sale is not clear, but, suffice to say, they were pulled and it is reported that Ace had to pay damages to both Tolkein and to Ballantine. The covers are reprinted below for your perusal.