H.R. 7995, An Act to limit the immigration of aliens into the United States . . . (Johnson-Reed Act), April 10, 1924
Congress enacted legislation in 1921 that set temporary annual quotas for immigrants based on their country of origin. As public pressure for added restrictions grew, Congress passed this bill in 1924, establishing permanent annual quotas for immigrants. Congress’s actions significantly reduced immigration from Southern and Eastern Europe and all but prohibited immigration from Asia and the Arab world.
Records of the U.S. Senate, National Archives and Records Administration
Investigating "Un-American" Activities and Restricting Immigration
World War I led to widespread concerns and speculation regarding threats to national security and democracy. Fear of “un-American” activities in the United States prompted the Senate to form the Overman Committee in 1918, which investigated possible pro-German, Bolshevik, and other activities and propaganda deemed dangerous to the nation. Public concern about the ethnic composition in the country and competition from foreign workers, meanwhile, pressured Congress to pass several laws in the early 1920s that banned or significantly restricted the number of immigrants admitted to the United States.
The nation having engaged in the greatest war in history with the purpose of saving the world for democracy, now emerges from that struggle confronted with the paramount duty of preserving democracy for the world.
“Senators Tell What Bolshevism in America Means,” The New York Times, June 15, 1919
Until now we have proceeded upon the theory that America was “the refuge of the oppressed of all nations,” and we have indulged the belief that upon their arrival here all immigrants were fused by the “melting pot” into a distinctive American type.
“America of the Melting Pot Comes to End,” The New York Times, April 27, 1924