Excerpt:
Germany had certainly developed its own body of eugenic knowledge and library of publications. Yet German readers still closely followed American eugenic accomplishments as the model: biological courts, forced sterilisation, detention for the socially inadequate, debates on euthanasia. As America's elite were describing the socially worthless and the ancestrally unfit as "bacteria," "vermin," "mongrels" and "subhuman", a superior race of Nordics was increasingly seen as the answer to the globe's eugenic problems. US laws, eugenic investigations and ideology became blueprints for Germany's rising tide of race biologists and race-based hatemongers.
One such agitator was a disgruntled corporal in the German army. In 1924, he was serving time in prison for mob action. While there, he spent his time poring over eugenic textbooks, which extensively quoted Davenport, Popenoe and other American ethnological stalwarts. And he closely followed the writings of Leon Whitney, president of the American Eugenics Society, and Madison Grant, who extolled the Nordic race and bemoaned its "corruption" by Jews, Negroes, Slavs and others who did not possess blond hair and blue eyes. The young German corporal even wrote one of them fan mail.
One day in the early 1930s, Whitney visited Grant to show off a letter he had just received from Germany, written by the corporal, now out of prison and rising in the German political scene. Grant could only smile. He pulled out his own letter. It was from the same German, thanking Grant for writing The Passing of the Great Race. The fan letter called Grant's book "his Bible". The man who sent those letters was Adolf Hitler.