President Calvin Coolidge signs into law the Immigration Act of 1924, the most stringent U.S. immigration policy up to that time in the nation’s history.

The new law reflected the desire of Americans to isolate themselves from the world after fighting World War I in Europe, which exacerbated growing fears of the spread of communist ideas. It also reflected the pervasiveness of racial discrimination in American society at the time. Many Americans saw the enormous influx of largely unskilled, uneducated immigrants during the early 1900s as causing unfair competition for jobs and land.

Under the new law, immigration remained open to those with a college education and/or special skills, but entry was denied to Mexicans, and disproportionately to Eastern and Southern Europeans and Japanese. At the same time, the legislation allowed for more immigration from Northern European nations such as Britain, Ireland and Scandinavian countries.

A quota was set that limited immigration to two percent of any given nation’s residents already in the U.S. as of 1890, a provision designed to maintain America’s largely Northern European racial composition. In 1927, the “two percent rule” was eliminated and a cap of 150,000 total immigrants annually was established.