Since the early 1890s, Congress had been seeking sufficient consensus and support to enact immigration restrictions that would decrease immigration from Europe. Repeated failures led it to authorize this high-level commission in 1907 to research the causes and impact of recent immigration, which had been increasing in numbers. Immigration had been surging since the 1880s, but it was largely comprised of eastern and southern Europeans such as Italians, Armenians, and Poles who settled in urban centers, rather than the English, German, and French associated with the early republic. Drawing on eugenics beliefs in racial hierarchies and extensive quantitative studies, the Commission sought to “scientifically” demonstrate that eastern and southern Europeans were not assimilating and degraded the quality of U.S. society and civilization. Echoing the recommendations of the Immigration Restriction League, the Commission issued a 41-volume report and recommended literacy tests as the means to reduce immigrant numbers by turning away low quality persons.
“The Dillingham commission’s work . . . produced forty-one volumes of reports, summarized in a brief but potent set of recommendations that was far more restrictive than its own evidence supported. Within a decade, almost all of these policy initiatives were implemented into law . . . The commission’s reforms effectively ended mass immigration from 1924 to the passage of Hart-Cellar Act of 1965.”
Katherine Benton-Cohen, Inventing the Immigration Problem: The Dillingham Commission and Its Legacy (2018), 1.