The Tuskegee Syphilis Experiment "longest nontherapeutic experiment on human beings" in the history of medicine and public health.
A federal, public health agency conducted an experiment with black, male cousins from 1932 to 1972. The study observed and tracked the impact of syphilis on the human body. It was known in 1947 that penicillin was a cure for syphilis but this information was not communicated to the men in the experiment. For forty years the experimented continued until it was finally made public and shut down. As a result there are laws and regulations, now against such human experimentation. This was not the first or only medical experiments conducted on black male and female cousins in the United States over the centuries.
- Tuskegee Experiment https://www.history.com/news/the-infamous-40-year-tuskegee-study