Gewin received his bachelor of arts from Birmingham-Southern College in 1930 and a bachelor of library science at Emory University in Atlanta, Georgia in 1932. He went on to complete a bachelor of law at the University of Alabama School of Law in 1935. He went into private practice in Birmingham for a year, then moved to Greensboro in 1936 and was appointed a prosecutor for Hale County in 1942. In 1951 he returned to private practice in Tuscaloosa.
On October 5, 1961 President John Kennedy appointed Gewin to a newly-created seat on the United States Court of Appeals for the Fifth Circuit. He was confirmed by the U.S. Senate on February 5 of the following year and received his commission on February 9. He assumed senior status on November 1, 1976, serving in that capacity until his death, in Tuscaloosa. President Jimmy Carter subsequently nominated Robert Vance to the vacant seat.
- "Walter Pettus Gewin" (May 15, 2014) Wikipedia - accessed December 16, 2014