Why was congress restrict immigration from Europe in 1920s?

In the 1920s, Congress restricted Immigration from Europe primarily due to a surge in nativism and a desire to preserve the existing cultural and racial makeup of the United States. The Immigration Act of 1924 established quotas that favored Northern and Western European immigrants while severely limiting those from Southern and Eastern Europe. These restrictions were fueled by economic concerns, fears of overpopulation, and the belief that new immigrants would exacerbate social problems. The legislation reflected broader societal anxieties about the impacts of immigration on American identity and labor markets.