During the early twentieth century thousands of Americans died of pellagra before the cause--vitamin B3 deficiency--was identified. Credit for ending the scourge is usually given to Dr. Joseph Goldberger of the U.S. Public Health Service, who proved the case for dietary deficiency during 1914-1915 and spent the rest of his life combating those who refused to accept southern poverty as the root cause. Charles S. Bryan demonstrates that between 1907...