Tolkien's influence

It was the advent of high fantasy and, most importantly, the popularity of J. R. R. Tolkien's The Hobbit and The Lord of the Rings which finally allowed fantasy to truly enter into the mainstream. Although Tolkien's works had been successful in Britain, it was not until the late 1960s that they finally became popular in America; however, at that point they began to sell steadily and in large numbers. Numerous polls to identify the greatest book of the century found The Lord of the Rings selected by widely different groups.
It is difficult to overstate the impact that The Lord of the Rings had on the fantasy genre; in some respects, it swamped all the works of fantasy that had been written before it, and it unquestionably created "fantasy" as a marketing category. It created an enormous number of works inspired by his books, using the themes found in The Lord of the Rings.
While fantasists had created fantasy worlds from the time of William Morris, Tolkien's influence enormously boosted them.
The impact that his books, helped cement the genre's popularity and gave birth to the current wave of fantasy literature.

 (J. R. R. Tolkien is considered to be one of the most important writers in fantasy literature)