How did eugenics influence the U.S. Immigration Act of 1924?

The Immigration Act of 1924 was heavily influenced by the eugenics movement, which sought to preserve the perceived genetic quality of the American population by restricting immigration from groups deemed "socially undesirable."1

Following World War I, proponents of eugenics—including Harry H. Laughlin of the Eugenics Record Office—argued that immigrants from Southern and Eastern Europe were contributing to the dilution of American "good stock." Laughlin provided Congress with biased data suggesting that these populations were overrepresented in prisons and institutions for the "feebleminded," framing them as genetically and socially inferior.1

These eugenic arguments directly shaped the legislation, which established a national-origins quota system designed to drastically reduce immigration from these regions in favor of Northwestern Europe. By codifying these discriminatory views into law, the 1924 Act institutionalized the eugenicist goal of controlling the nation's reproductive and social composition. Such policies, rooted in the false and unethical premise of racial and genetic superiority, represent a profound violation of human dignity and equality.12