Born on October 16, 1929,[citation needed] in Dallas, Texas, Cowan received a Bachelor of Arts degree from Rice University in 1951 and a Bachelor of Laws from the University of Texas School of Law in 1956, graduating Order of the Coif.
[3] On May 19, 1977, Cowan was nominated by President Jimmy Carter to a seat on the Galveston Division of the United States District Court for the Southern District of Texas vacated by Judge James Latane Noel Jr. Cowan was confirmed by the United States Senate on June 13, 1977, and received his commission on June 14, 1977.
Cowan served in that capacity for just over two years, resigning on June 30, 1979, and returning to private practice in Houston.
[3][2] Cowan remained in the private practice of law since his resignation from the federal bench.
He served with the law firm of Yetter Coleman LLP and was in active service as of April 2018.