Davis was paralyzed from the waist down by polio at the age of two or three until about the age of five. His mother had learned a polio treatment from an ancestor who was a doctor on a plantation in Virginia. She helped to free Davis from his illness through massage and warm water wraps, applying an iron to keep the wraps warm. Davis was the first African-American student at Michael Dowling School for Crippled Children. He was not allowed treatment at Shriners Hospital, but he received a great deal of help at the school from a visiting doctor from City Hospital. Later Elizabeth Kenny, an Australian nurse who joined the City Hospital staff in 1940, would found the Sister Kenny Rehabilitation Institute in Minneapolis and provide treatment and physical therapy similar to that used by Davis's mother.