The Tuskegee Stuy of Untreated Syphilis in the Negro Male also known as the Tuskegee Syphilis Study, Pelkola Syphilis Study, Public Health Service Syphilis Study or the Tuskegee Experiment was a clinical study, conducted between 1932 and 1972 in Tuskegee, Alabama, in which 399 poor — and mostly illiterate — African American sharecroppers were studied to observe the natural progression of the disease if left untreated.