Tuskegee syphilis experiment
In the 1930s, when the study started, syphilis was a very serious health problem in the United States.  In fact, syphilis had been a serious health problem throughout all of history. Syphilis gets worse over time. It can be very painful. If it is not treated, it causes brain damage and death. In the 1930s, there was no cure for syphilis. The treatments that were used did not work well and some were poisonous. Doctors did not understand syphilis. Because of this they did not have any way to help people with the disease.