Born into a family of sharecroppers in Chipley, Georgia, in 1924, Alton Cadenhead developed an early interest in engineering. He even attempted to harness energy from a creek that flowed near his home by installing a homemade paddle wheel. When the local school system went bankrupt during the Great Depression, Cadenhead and his siblings drove to the neighboring county to attend school. After graduating from high school, Cadenhead attended a satellite school of the University of Georgia on a work scholarship sponsored by the Callaway Foundation. He was pursuing an engineering degree when the Empire of Japan attacked Pearl Harbor.
Cadenhead wanted to enlist in the Marine Corps because of its small, well-trained units, but he was deferred for one year because of a weak leg. He continued to attend college and exercised daily to build his strength. He married Ila Walls, the daughter of the manager of the mill where he worked, in 1942. The following year Cadenhead reenlisted in the Marine Corps and completed his training at Camp Lejeune in North Carolina.
As a corporal in the Third Marine Division, Cadenhead served in the Battle of Guam, where he helped take the capital city of Agana from the Japanese in the summer of 1944. During the battle Cadenhead suffered head injuries and temporarily lost his hearing. In the Battle of Iwo Jima in 1945, he was injured when shrapnel pierced his left arm. After the war Cadenhead worked in the Marine Engineer Corps before returning to the United States. Reintegrating into civilian life was difficult for Cadenhead, but he eventually completed his engineering degree and designed carpet manufacturing plants in North Georgia. The owner of ten patents, Cadenhead lives in Calhoun, Georgia today.