J.R.R Tolkien’s “The Lord of the Rings” is often erroneously called a trilogy when it is actually one book often published in three volumes! The Lord of the Rings is a single novel with six books and appendices. It is sometimes published in 3 volumes and people erroneously call it a trilogy.
The reason for this was that paper was scarce and expensive at the time, so the publisher decided that it would be better to publish it in 3 volumes, so that they could recoup the cost of paper.
The first volume, “The Fellowship of the Ring” was first published in Great Britain in July 1954 and in the U.S. in October 1954. The publication of the first volume began a problem that Tolkien continued facing with each volume published.
The editors made many well-intentioned corrections that actually ruined what Tolkien had tried to write. Instead of Tolkien’s “elven” they would correct it to “elfin” or “dwarves” to “dwarfs.” Tolkien’s invented language was continuously “corrected,” something he constantly fought to get reverted back to his original writing.
The second volume, “The Two Towers,” was published in Great Britain in November 1954 and in the U.S. in April 1955. The third volume was delayed, because Tolkien had promised in his first volume that he would add an index and full etymological information on the languages, especially on the elven tongues.
In the end, there wasn’t an index in the third volume, only an apology from the publisher for the lack of index. Volume three was finally published in October 1955 in England and January 1956 in the U.S.