The foreign born population in the U.S. is only 14%, which is actually near the historic high. https://www.pewresearch.org/fact-tank/2020/08/20/key-finding...

Our cultural identity is one of a nation of immigrants, but over the past couple decades many European countries have become just as much if not more so. Among OECD countries the U.S. is middle of the pack: https://data.oecd.org/migration/foreign-born-population.htm