Dwight Davis, a Seattle native, attended the University of Washington before serving as an Air Force medical corpsman. He married Esperanza Esparza. He began attending pre-med school and worked at Brackenridge Hospital where he met Earl Rhine. Rhine and Davis both attended the University of Texas in 1954 and then Southwest Texas State College in 1955 for pre-med until they went to work for Dr. Tom Dooley in Laos in 1958.

         In 1958, Rhine and Davis read about Dr. Tom Dooley's medical work in Southeast Asia and his new organization MEDICO in national magazines. They contacted him about working with him, and after an interview, Dr. Dooley invited them to be his new MEDICO team and work with him in Laos. Their wives stayed in Texas and worked while their husbands were in Laos. Rhine and Davis left in July 1958 and began work with Dr. Dooley at a hospital they established in Muong Sing, Laos.

         While in Laos, Rhine and Davis assisted Dr. Dooley with operations and delivering babies and treated tuberculosis, pneumonia, malaria, small pox, whooping cough, leprosy, beri-beri, respiratory infections, vitamin deficiencies, malnutrition, and much more.

         Rhine and Davis returned to the United States in April 1960. They returned to Southwest Texas State College and earned their pre-med degrees. After they graduated, Rhine and Davis were recruited by the State Department to work with the Agency for International Development (AID) program. They worked in separate villages in South Vietnam. The goal of their work was to help villagers learn to grow various crops and use new farm equipment so they could produce for themselves. They worked in South Vietnam from 1962 to 1965.

         In 1966, Rhine and Davis began work for the Office of Economic Opportunity. They worked with locally elected officials, business people, and the poor of specific areas to determine the cause of poverty in that area, and then to design a way to get the area out of poverty. Later, Rhine worked with the Health and Human Services, and Davis worked for the Environmental Protection Agency.