Actually J.R.R.Tolkein worte "The Hobbit" between the world wars.
It was successfull so he was asked to write more about hobbits.
The result after 10 years of writing was the Lord of the Rings,
intended to be one book like "War and Peace". The publisher
insisted it be broken into 3 books as they didnt think it would
sell as one. The Lord of the Rings didnt do all that well for nearly
20 years. It was popular on college campuses in the U.S.
in the 60s and 70s before most of the general public in the
States knew about it.