What is Emergency Quota Act?

Legal Definition
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 two new features to American immigration law: numerical limits on immigration and the use of a quota system for establishing those limits. These limits came to be known as the National Origins Formula.

The Emergency Quota 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. This meant that people from northern European countries had a higher quota and were more likely to be admitted to the U.S. than people from eastern Europe, southern Europe, or other, non-European countries. Professionals were to be admitted without regard to their country of origin. The Act set no limits on immigration from Latin America. The act did not apply to countries with bilateral agreements with the US, or to Asian countries listed in the Immigration Act of 1917, known as the Asiatic Barred Zone Act.

Based on that formula, the number of new immigrants admitted fell from 805,228 in 1920 to 309,556 in 1921-22. The average annual inflow of immigrants prior to 1921 was 175,983 from Northern and Western Europe, and 685,531 from other countries, principally Southern and Eastern Europe. In 1921, there was a drastic reduction in immigration levels from other countries, principally Southern and Eastern Europe.

Following the end of World War I, both Europe and the United States were suffering economic and social upheaval. In Europe, the destruction of the war, the Russian Revolution, and the dissolution of both the Austro-Hungarian Empire and Ottoman Empire led to greater immigration to the United States, while in the United States an economic downturn following post-war demobilization increased unemployment. The combination of increased immigration from Europe at the time of higher American unemployment strengthened the anti-immigrant movement.

The act, sponsored by Rep. Albert Johnson (R-Washington), was passed without a recorded vote in the U.S. House of Representatives and by a vote of 90-2-4 in the U.S. Senate.

The Act was revised by the Immigration Act of 1924.

The use of such a National Origins Formula continued until 1965 when the Immigration and Nationality Act of 1965 replaced it with a system of preferences based on immigrants' skills and family relationships with U.S. citizens or U.S. residents.
-- Wikipedia