Answer: Passage of restrictive immigration quotas
Explanation: The cited passage reflects a yearning for halting immigration and fostering a homogeneous, uncontaminated American populace comprised solely of individuals who possess a pure, unadulterated Anglo-Saxon lineage. Such inclinations were ubiquitous among nativist politicians and advocates during the beginning of the 20th century, resulting in the approval of laws that curtailed immigration from certain nations, while ushering in immigrants from Western and Northern Europe. The establishment of nationality-based quotas under the Immigration Act of 1924 was a direct outcome of the pervasive patriotic and nationalist sentiments prevailing during that time.