David Laurence Thomas was born on March 2, 1922 to Carl and Lillian Thomas, who lived in West Chester, Pennsylvania. He was one of seven children.
David was a birthright member of the High Street Friends Meeting in West Chester. He attended the private Westtown School. At Westtown, David was on the Dance Committee, an important committee, as dances were first permitted at the school in 1938-39. He was also a member of the Senior Hiking Club and the Rustic Club, a popular agriculture club. David graduated from Westtown School in the Class of 1940.
David entered the Army Air Forces in February, 1943, receiving his commission as an officer and B-17 pilot at Waco Texas in April, 1943. David was then sent overseas to fly B-17 bombers in the 339th Bomber Squadron, 96th Bomber Group, Heavy, Eighth Air Force based in Snetterton Heath, England.