Sam Lunsford was born on December 12, 1919, in Dorchester, Virginia. He enlisted in the U.S. Navy on September 13, 1938, and completed basic training at NTS Norfolk, Virginia, in December 1938. His first assignment was as a fireman aboard the battleship USS New York (BB-34) from January 1939 to February 1940, followed by service as an electrician's mate and fireman aboard the destroyer USS Buchanan (DD-131) from February to August 1940. EM3c Lunsford served aboard the submarine USS S-22 (SS-127) from August 1940 to June 1941, and then aboard USS O-3 (SS-64) and USS O-8 (SS-69) for submarine training at Submarine Base New London, Connecticut, from June 1941 to March 1942. EM2c Lunsford joined the crew of the USS Grunion (SS-216) during her fitting out in March 1942, and remained aboard after her commissioning in April 1942. He was killed in action aboard the Grunion during a confrontation with the armed Japanese freighter Kano Maru on July 30, 1942. On August 22, 2007, a search team organized by the three sons of CDR Mannert Abele (the Captain of the Grunion when she was sunk) used a remotely operated vehicle to find a sunken vessel 3,000 feet down in the Bering Sea north of Kiska Island at the tip of the Aleutian Islands. On October 1, 2008, the U.S. Navy announced that the sunken vessel is the World War II submarine USS Grunion (SS-216).

His Navy Commendation Medal Citation reads:

For meritorious conduct as a member of the crew 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 a member of the crew of the GRUNION, your performance of duty was an important and material contribution to the prosecution of this war.