The Tuskegee Syphilis Experiment (/tʌsˈkiːɡiː/) was a clinical study. The study was done between 1932 and 1972 by the United States Public Health Service. Its goal was to study how syphilis progressed (got worse) if it was not treated. The study's subjects (the people who were being studied) were poor African American sharecroppers. They were told that they were receiving free health care from the U.S. government.