Final answer:
The American eugenics movement was a misguided attempt to improve the human race through selective breeding, which led to forced sterilizations and discrimination, influenced by racism and xenophobia, and had lasting impacts including the legitimization by the Supreme Court and the adoption of similar practices by Nazi Germany.
Step-by-step explanation:
The American eugenics movement of the early 20th century was a pseudo-scientific initiative fueled by the idea that public health and the genetic makeup of the human race could be improved through selective breeding. This movement was supported by notable foundations and characterized by significant medical exploitation, including the forced sterilization of tens of thousands, targeting primarily people of color, the mentally ill, those with disabilities, and other marginalized groups. Its rationale was laced with racism, xenophobia, and ableism, and it led to discriminatory policies such as anti-miscegenation laws and residential segregation. The severe consequences of these policies, such as the institutionalization and sterilization without consent, were sanctioned by the 1927 Supreme Court case of Buck v. Bell. Eugenics fell into disrepute when Nazi Germany adopted and expanded upon these practices to horrific levels during the 1930s and '40s, which partially modeled their sterilization and eugenicide programs on American precedents.