Emergency Quota Act

The Emergency Quota Act, also known as the Emergency Immigration Act of 1921, the Immigration Restriction Act of 1921, the Per Centum Law, and the Johnson Quota Act (ch. 8, 42 Stat. 5 of May 19, 1921) restricted immigration into the United States. Although intended as temporary legislation, the Act "proved in the long run the most important turning-point in American immigration policy" because it added 2 new features to American immigration law: numerical limits on immigration from Europe and the use of a quota system for establishing those limits.

The Act restricted the number of immigrants admitted from any country annually to 3% of the number of residents from that same country living in the United States as of the U.S. Census of 1910. Based on that formula, the number of new immigrants admitted fell from 805,228 in 1920 to 309,556 in 1921-22.

The act meant that only people of Northern Europe who had similar cultures to that of America were likely to get in. The excuse was the American government wanted to protect its culture when this act was introduced, however some felt it was mainly in response to the millions of Jews who begun fleeing the terrible persecution they were facing in Western Europe starting in 1890. The fact that the quotas were to be based on the 1910 census, immediately prior to the influx of those Jews, rather than the 1920 census, lends credence to that accusation.