His father was killed when he was six and his mother was placed in a mental hospital when he was thirteen, after which he lived in a series of foster homes. In 1946, at age 20, he went to prison for larceny and breaking and entering. While in prison, he became a member of the Nation of Islam (NOI), changing his birth name Malcolm Little to Malcolm X because, he later wrote, Little was the name that "the white slavemaster . . . had imposed upon [his] paternal forebears". After his parole in 1952, he quickly rose to become one of the organization's most influential leaders, serving as the public face of the controversial group for a dozen years. In his autobiography, Malcolm X wrote proudly of some of the social achievements the Nation made while he was a member, particularly its free drug rehabilitation program. The Nation promoted black supremacy, advocated the separation of black and white Americans, and rejected the civil rights movement for its emphasis on integration.