How did the rise of eugenics in the early 20th century influence immigration policy?

The rise of eugenics in the early 20th century significantly influenced immigration policy by promoting discriminatory practices aimed at limiting immigration from specific countries, particularly those deemed to have "undesirable" populations. Eugenics, a movement that sought to improve the genetic quality of the human population through selective breeding, was based on flawed scientific principles that categorized certain races and ethnicities as superior to others.

As eugenics gained traction in society, it contributed to the belief that immigration from certain regions, particularly Southern and Eastern Europe, posed a threat to the perceived social and biological integrity of the nation. This led to the implementation of restrictive immigration laws, such as the Immigration Act of 1924, which established quotas that severely limited entry for individuals from countries considered to be inferior in terms of their supposed genetic makeup.

This ideology underpinned many legislative acts, fostering an environment of fear and prejudice that shaped public opinion and created barriers for immigrants seeking to enter the United States. The emphasis on eugenics reflected a broader concern among some segments of society regarding race, ethnicity, and national identity, ultimately leading to more exclusionary immigration policies that were informed by these discredited beliefs.