Immigration Act of 1924

The Immigration Act of 1924, or Johnson–Reed Act, including the Asian Exclusion Act and 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 every country outside Latin America. 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. Immigrants from Asia were banned, and the total annual immigration quota for the rest of the world was capped at 165,000—an 80% reduction of the yearly average before 1914. The act temporarily reduced the annual quota of any nationality from 3% of their 1910 population, per the Emergency Quota Act of 1921, to 2% as recorded in the 1890 census; a new quota was implemented in 1927, based on each nationality's share of the total U.S. population in the 1920 census, which would govern U.S. immigration policy until 1965.

According to the Department of State, the purpose of the act was "to preserve the ideal of U.S. homogeneity." The 1924 act would define U.S. immigration policy for nearly three decades, until being substantially revised by the Immigration and Nationality Act of 1952 and ultimately replaced by the Immigration and Nationality Act of 1965.