Following the enactment of strict country-of-origin quotas in the early 1920s, immigration rates to the United States dropped dramatically.
The Emergency Quota Act of 1921 limited annual immigration rates to only three percent of the total population of residents from that same country living in the United States. While intended to be temporary, this 1921 Act established the quota system into American immigration law. The Johnson-Reed Act of 1924 further tightened quotas and expanded prohibitions against Asian immigrants, including those from Japan. Immigration rates dropped more than 50 percent the following year. President Calvin Coolidge, who signed the 1924 law, wrote: “Biological laws tell us that certain divergent people will not mix or blend. The Nordics propagate themselves successfully. With other races, the outcome shows deterioration on both sides.” In 1924, Congress also established the (see also:Border Patrol established, 1924].