[3] Parker worked in private legal practice in Gilmer, Texas from 1964 until 1965, and then in his native Longview in 1965.
From 1965 until 1966, he worked as an administrative assistant to United States Representative Ray Roberts.
He then worked in private law practice in Longview from 1966 until 1971, in private legal practice in Fort Worth from 1971 until 1972, and back in Longview as a partner in the firm Nichols & Parker from 1972 until joining the federal bench in 1979.
[3] Parker was nominated by President Bill Clinton on January 27, 1994, to a seat on the United States Court of Appeals for the Fifth Circuit vacated by Judge Samuel D. Johnson, Jr.
[3] After his retirement from the federal bench, Parker returned to private practice.