William A. DeMonbreun received his B.A. from the University of Tennessee in 1921, his M.S. from Vanderbilt University in 1922, and M.D. degree from Vanderbilt University School of Medicine in 1927. He was one of the major researchers in histoplasmosis, often been referred to as the 'Vanderbilt disease' since most of the major research on the subject was conducted at Vanderbilt University School of Medicine during the 1930s and 1940s. DeMonbreun succeeded in culturing the fungus of the disease and his paper resulting from his work was presented at the November 1933 meeting of the American Society of Tropical Medicine.

DeMonbruen was both Associate Professor Emeritus of Pathology at Vanderbilt University School of Medicine and consultant pathologist at Nashville General Hospital at the time of his death. He died in 1968.