Born in New Orleans, Louisiana, to Henry D. and Ruby (née Price), McNamara graduated from the Roman Catholic Jesuit High School in 1954.

[1] From 1966 to 1968 he was a bailiff and law clerk for United States District Judge Herbert William Christenberry.

[3] On May 5, 1982, President Reagan nominated McNamara to a seat on the United States District Court for the Eastern District of Louisiana vacated by Judge Edward James Boyle Sr.

He served as Chief Judge from 1999 to 2001, assuming senior status on June 9, 2001.

[2] McNamara was succeeded on the court by Judge Jay C. Zainey, a nominee of President George W. Bush, who was confirmed on October 10, 2001.