The Immigration Act of 1924, or Johnson–Reed Act, including the National
Origins Act, and Asian Exclusion Act, was a United States federal law
that limited the annual number of immigrants who could be admitted from
any country to 2% of the number of people from that country who were
already living in the United States as of the 1890 census, down from the
3% cap set by the Emergency Quota Act of 1921, which used the Census of
1910. The law was primarily aimed at further restricting immigration of
Southern Europeans and Eastern Europeans, especially Italians, Slavs
and Eastern European Jews. In addition, it severely restricted the
immigration of Africans and banned the immigration of Arabs and Asians.
