Mary Ada Cox Gage Dunham grew up in Mount Olive, North Carolina, and graduated from Mount Olive High School. She attended the Woman’s College of the University of North Carolina (now the University of North Carolina at Greensboro), where she studied art, and graduated in 1944.
Dunham joined the U.S. Navy WAVES immediately after her graduation in the spring of 1944. She attended basic training at Smith College in Northampton, Massachusetts, and was then stationed in Washington, D.C., as an archivist of decoded messages.
Dunham left the WAVES as an ensign in 1946 and married Bob Gage. They moved to Indiana, where her husband worked for Union Carbide, and they had three sons. After her first husband died, she married a long-time friend, Milton Dunham.