I Am Legend is a 1954 science fiction horror novel by American writer Richard Matheson. It was influential in the development of the zombie-vampire genre of fiction, and in popularizing the concept of a worldwide apocalypse due to disease. The novel was a success and was adapted into the plot of films, namely: The Last Man on Earth (1964), The Omega Man (1971), I Am Legend (2007), and the direct-to-video production I Am Omega (2007). The novel was also an inspiration behind Night of the Living Dead (1968).

Can we conclude that was the book legend made into a movie?
yes