Matthews was born on Dec. 31, 1931, in the Van Nuys neighborhood of Los Angeles. His parents were William and Nettie, and he had six siblings: three sisters and three brothers, one of whom was his twin.
Matthews ran track and played football for Van Nuys High School before dropping out in 1948 when he was about 17 to work as a concrete-mixer operator for C.W. Organ, a Los Angeles contracting company. On Feb. 21, 1951, several months after the Korean War broke out, Matthews enlisted in the Marine Corps. He was assigned to Camp Pendleton and, by 1952, had earned the rank of sergeant.
Matthews left for Korea in January 1953. A month later, he was assigned to the 2nd Battalion, 7th Marines, 1st Marine Division.
Matthews had been in Korea for less than three months when enemy troops launched an attack on Vegas, a hilly U.S. command outpost north of the main line of resistance around the 38th Parallel. Two other U.S. manned outposts were attacked simultaneously. The battle for these outposts would last for five days.
The initial attack on Vegas forced the Marines from their least defensible positions, and artillery fire destroyed most of their telephone wires for communications. By the end of the first night of fighting, the Chinese controlled the outpost and were dug in on the hill, using its complex trenches and bunkers for cover.
Marines spent the next two days trying to win Vegas back.
By the third day of fighting, March 28, Matthews' 2nd Battalion had been called in as a reserve unit to help. The young sergeant was serving as a squad leader for Company F.
The company tried and failed twice before it finally made headway toward the entrance to the outpost's trenches. Matthews was able to move his squad forward until they were pinned down by machine gun fire coming from the top of the hill. At that time, Matthews noticed that the deadly fire was also keeping a medic from moving a wounded Marine, who was exposed in an open area. He knew he had to get the fire to stop somehow.
Thinking quickly, Matthews worked his way up the hill to the base of the enemy machine gun nest and leapt onto the rock fortification surrounding it. He surprised the enemy soldiers and charged them with his rifle.
The enemy turned their guns on Matthews, seriously wounding him, but he kept up his one-man assault. He was able to kill two enemy soldiers and force a third to run away, silencing the enemy gun. His effort made it possible for the medic to evacuate the wounded Marine.
In saving that man's life, Matthews gave his own. The 21-year-old died from his wounds before aid could reach him.
Two days later, the siege of the hill ended, and enemy forces were repelled from Vegas. The five-day battle was one of the bloodiest Marine engagements during the Korean War.
Four months later, an armistice agreement was signed, and the hostilities ended.
David Matthews, who at the time was a Navy machinist's mate, helped escort his twin's body back to the U.S. in May 1953. The young Marine was buried in Glen Haven Memorial Park in San Fernando, California.
On March 29, 1954, Matthews' parents were presented with the Medal of Honor by Navy Secretary Robert B. Anderson during a Pentagon ceremony. Matthews' twin brother was again in attendance. The families of two other fallen Marines — Sgt. James E. Johnson and Cpl. Lee H. Phillips — also received posthumous medals that day.