Answer:
One effect of the Johnson-Reed Act of 1924 was that immigration from eastern and southern Europe all but stopped.
Step-by-step explanation:
The Johnson-Reed Act or Immigration Act of 1924 was a statutory immigration regulatory regime for the United States of America that ran from 1924 to 1965. It included, as supplementary legislation, the National Origins Act And the Asian Exclusion Act, creating a federal legal regime limiting the number of immigrants who could be admitted to the United States to a maximum of 2% of the the total number of persons with that national origin who had already resided in the country in 1890. That percentage was a reduction from the 3% limit set by the Immigration Restriction Act of 1921, which also took as a reference to the result of the population census of 1890. That law replaced the Emergency Quota Act of 1921 and was intended to curb the growth of the migration of southern Europeans, mostly Roman Catholics, and Slavs and Jews from Eastern Europe, who had begun arriving in the United States in large numbers from the 1890s, and to prohibit the entry of Asians, Indians and non-European citizens who were not eligible for naturalization.