463 - The Tuskegee Study (Secret, Deadly Medical Testing on American Citizens)
From 1932 to 1972, six hundred poor, black sharecroppers in Alabama were told they were being treated for "bad blood," when in reality, the US government was conducting an experiment on how untreated syphilis affected their bodies, a study that was supposed to keep going until every participant was dead. A study that would've kept going, had a whistleblower not exposed it.