Indiana in 1907 became the first U.S. state to pass a eugenics law making sterilization mandatory for certain types of people in state custody.Thirty different states and Puerto Rico soon followed with laws of their own.In the first half of the twentieth century, approximately sixty thousand Americans, mostly patients in mental institutions and criminals, were sterilized without their acquiescence.Roughly a third of all Puerto Rican women were sterilized after providing only the flimsiest consent.These laws were not entirely uncontroversial, and many were challenged in courts.But the U.S. Supreme Court ruled in its now infamous 1927 Buck v. Bell decision, that eugenics laws were constitutional.“Three generations of imbeciles,” progressive Supreme Court justice Oliver Wendell Holmes disgracefully wrote in the decision, “are enough.”

As the eugenics movement played out in the United States, another group of Europeans was watching closely.Nazism was, in many ways, a perverted heir of Darwinism.