Final answer:
In the 1920s, immigrants from Southern and Eastern Europe were the primary targets of prejudice and restrictive immigration legislation, such as the National Origins Act of 1924, which limited their number through quotas and fomented discrimination.
Step-by-step explanation:
The major target of prejudice and immigration legislation in the 1920s were immigrants from Southern and Eastern Europe, including Jews, Italians, Czechs, Poles, Russians, and other groups. This discrimination was a continuation of the nativism and xenophobia that characterized American sentiment towards these newer immigrants. Prejudices against these groups were solidified with the passing of the National Origins Act of 1924, which created quotas based on the national origins listed in the 1890 census, and effectively restricted immigration from these regions.
These immigrant groups faced significant discrimination and were frequently blamed for social and economic problems within American cities. Italian immigrants, for instance, lived in segregated slums and were paid less for labor-intensive jobs. The scapegoating and animosity towards these groups were not only social but also institutional, as seen through legislation like the aforementioned National Origins Act of 1924 and earlier acts such as the Literacy Test of 1917.
Although earlier immigrant groups, like the Irish and Germans, were able to eventually assimilate into American society, the newer immigrants from Southern and Eastern Europe continued to face prejudice and legal barriers in the 1920s due to the strong influence of nativism on America's immigration policy.