How many installments was Lord of the book?

The Lord of the Rings was published in three installments:

* The Fellowship of the Ring (1954)

* The Two Towers (1954)

* The Return of the King (1955)

However, it's important to note that these installments were originally intended to be one single book. J.R.R. Tolkien's publisher suggested splitting it into three volumes due to its size.