Nixon was in private practice as a lawyer in Anniston, Alabama, from 1960 to 1962. He served as city attorney of Anniston from 1962 to 1964. He was a trial attorney of the Civil Rights Division of the United States Department of Justice from 1964 to 1969. He returned to private practice from 1969 to 1971. He then served as a staff attorney of Office of the State Comptroller in Tennessee from 1971 to 1976. Moving to Nashville, Tennessee, in 1976, he practiced law there until 1977. He then served as a judge of the Circuit Court of Tennessee from 1977 to 1978, and as a judge of the Tennessee Court of General Sessions from 1978 to 1980.
