I came across a really interesting article on Wikipedia titled Unethical Human Experimentation in the United States. Many of these experiments were government initiated and funded which is rather frightening.
A couple of the most interesting reads are the Tuskegee Syphilis Experiment and Project MKULTRA (which isn’t just some conspiracy theorist malarkey, but an actual series of CIA experiments that later lead to a congressional hearing). It’s worth taking some time out of your day and reading through these because some of them are almost unbelievable.