Authorized by the US Public Health Service (PHS) and Tuskegee Institute, “Untreated Syphilis in the Negro Male” was one of the most inhumane medical experiments in the twentieth century. Centered in Macon County, Alabama and enrolling 600 poor black men, 399 infected and 201 noninfected, the experiment began in 1932 and lasted until 1972, when public censure forced its termination.

It enjoyed official sanction. Subjects received free meals, physical examinations, and burial costs. Syphilitic subjects were never informed of their disease, merely told that they had “bad blood.” Penicillin became available for treatment of syphilis in the 1940s, but they did not get it. Instead, while infected men suffered, doctors studied their syphilitic symptoms. Many endured painful deaths; eight survived. Five of them attended a White House ceremony to hear the president's apology (1977). Since that time the federal government has paid more than $10 million in compensation to the men's survivors and heirs.