When I was a young skull full o’ mush my mother made me read a book about the Eugenics Movement (she was very involved in Pro Life causes)
One of these books opened with a long historical speech on the subject. It invited you to guess whether it was the work of Hitler or Teddy Roosevelt. Then it invited you to turn the page for the answer.
It wasn’t Hitler.
Was a real eye opener as virtually none of this was taught in my history classes at school.
The euthanasia the Nazis implemented on the mentally ill, genetically flawed at the time was an ideology, practice taken from American doctor, geneticist pioneers in the field in the 1920’s.