Griffith chose to explore the theme of intolerance partly in response to his previous film "The Birth of a Nation" (1915) being criticized by the NAACP and other groups for perpetuating racial stereotypes and glorifying the Ku Klux Klan. "Intolerance" was not, however, an apology, as Griffith felt he had nothing to apologize for; in numerous interviews, Griffith made clear that the film was a rebuttal to his critics and he felt that they were, in fact, the intolerant ones. In the years following its release, "Intolerance" would strongly influence European film movements. In 1989, it was one of the first films to be selected for preservation in the United States National Film Registry.