Tuskegee syphilis experiment
By 1947, penicillin had become the normal treatment for syphilis.  It was not just a treatment, but a cure.  The United States government created several public health programs to help people get the cure.  The government formed "rapid treatment centers" where people could go for penicillin.  The governments goal was to eradicate syphilis (to make it not exist any more).  But when these programs came to Macon County, study researchers kept the Tuskegee men from participating.