The Immigration Act of 1924, also known as the Johnson–Reed Act, or National Origins Act (Pub. L. 68–139, 43 Stat. 153, enacted May 26, 1924), was a United States federal law that prevented immigration from Asia and set quotas on the number of immigrants from Eastern and Southern Europe. It also authorized the creation of the country's first formal border control service, the U.S. Border Patrol, and established a "consular control system" that allowed entry only to those who first obtained a visa from a U.S. consulate abroad.
The 1924 act was passed due to growing public and political concerns about the country's fast-changing social and demographic landscape. It replaced earlier legislation by significantly reducing immigration from countries outside the Western Hemisphere.