Years before Adolph Hitler obtained power, and in the decades before the Third Reich brought “the manufacture of mass death to its pitiless consummation” in the words of the late military historian John Keegan, the seeds were planted of America’s callous and ineffective response to the Nazi persecution of Europe’s Jews. As the filmmakers Ken Burns, Lynn Novick, and Sarah Botstein show in their searing new documentary “The U.S. and the Holocaust,” hostility to immigration coexisted with America’s reputation as a land of opportunity during an era that saw millions of Europeans make their way to Ellis Island. But a long-simmering nativist backlash combined with the junk science of eugenics to produce federal legislation in 1924 severely restricting emigration to the United States based on nation of origin. These quotas, which enjoyed widespread public and political support, would prevent hundreds of thousands of Jews from escaping Europe when they had a chance. In this episode, author and historian Rebecca Erbelding, an expert on the U.S. response to the Nazi genocide at the U.S. Holocaust Memorial Museum and an independent scholarly advisor to the Burns documentary, discusses the ways in which antisemitism, nativism, and isolationism contributed to the failure to save more Jewish lives. Americans expressed revulsion at Nazi violence, but the outrage did not lead to a more welcoming attitude toward refugees.