Sam Dighton was born on December 13, 1917, in Savannah, Georgia. After receiving his bachelor's degree from the University of Alabama in June 1939, he enlisted in the U.S. Naval Reserve on September 20, 1940, and went on active duty beginning November 25, 1940. After serving for a month aboard the battleship USS New York (BB-34), he was accepted into the U.S. Naval Midshipmen's School at Northwestern University in Chicago, Illinois on December 21, 1940. Dighton was commissioned an Ensign in the U.S. Navy on May 15, 1941, and then served aboard the submarine USS Mackeral (SS-204) from June to September 1941. Ens Dighton next attended Submarine School at New London, Connecticut, from September to December 1941, followed by service at Groton, Connecticut, in connection with the fitting out of the submarine USS Grunion (SS-216) from December 1941 until the submarine was commissioned in April 1942. LT Dighton remained aboard USS Grunion as First Lieutenant through her commissioning in April 1942, until he was killed in action during a confrontation with the armed Japanese freighter Kano Maru on July 30, 1942. The ship was found by a search team on August 22, 2007, and the U.S. Navy announced the sunken vessel located off the coast of the Aleutian Islands is the World War II submarine USS Grunion (SS-216) on October 1, 2008.

His Navy Commendation Medal Citation reads:

For meritorious conduct as First Lieutenant of the U.S.S. GRUNION which destroyed three enemy destroyers while engaged in a war patrol in enemy controlled waters. Despite severe and persistent anti-submarine measures resulting from these three successful attacks, the GRUNION was brought safely through the counter attacks and continued an aggressive war patrol. As First Lieutenant of the GRUNION, your performance of duty was an important and material contribution to the prosecution of this war.