Although Nazi racial policy represented the most extreme form of eugenics legislation, the particular brand of eugenics that took place in Germany was only one element of a much broader, international embrace of eugenics research and policies. In particular, the researchers, politicians and activists who crafted eugenics legislation and gave it the force of science were primarily based in the U.S., and the Nazis referred often to the pioneering work of the U.S. group. A good deal of cooperation and collaboration took place between American and German eugenicists as well, including the exchange of ideas. Marie E. Kopp was an American proponent of eugenics and travelled to Germany in 1932 and 1935, conducting studies on the application of German eugenics policy between those years. Kopp proved influential in American eugenics circles, advocating on behalf of Nazi race policy. At the 25th meeting of the Eugenics Research Association in NYC in 1937, she told the assembly that she was convinced not only that Germany’s race laws were implemented “in entire fairness” and that discrimination played no role, but that Nazi policies were set to ensure the health of the nation by encouraging racially pure, healthier and superior human beings. She praised Germany’s policy of removing women from the labor force to ensure young men could achieve employment and marry early, and that women could raise children in “proper” conditions.

Another prominent eugenicist, Charles M. Goethe, helped found the Eugenics Society of Northern California and the Immigration Study Commission, and was president of the American Eugenics Research Association. Goethe wanted to severely restrict immigration from Latin America and especially Mexico. He was also president of the Goethe Bank, which necessitated frequent travel to Germany, where he studied Nazi eugenics policies in action. In letters home, Goethe reflected on the extent to which American eugenics thinking had influenced Germany’s policies – particularly the work of eugenicist Eugene S. Gosney, and called for America to adopt similar policies.