http://en.wikipedia.org/wiki/Tuskegee_syphilis_experiment"he Tuskegee syphilis experiment[1] (also known as the Tuskegee syphilis study or Public Health Service syphilis study) was an infamous clinical study conducted between 1932 and 1972 in Tuskegee, Alabama by the U.S. Public Health Service to study the natural progression of untreated syphilis in rural black men
who thought they were receiving free health care from the U.S. government.[1]"