https://en.wikipedia.org/wiki/Demographics_of_the_United_States https://en.wikipedia.org/wiki/Demographics_of_the_United_Sta... Foreign-born immigration caused

https://en.wikipedia.org/wiki/Demographics_of_the_United_States https://en.wikipedia.org/wiki/Demographics_of_the_United_Sta... Foreign-born immigration caused the U.S. population to continue its rapid increase, with the foreign-born population doubling from almost 20 million in 1990 to over 45 million in 2015,[19] representing one-third of the population increase.[20] The U.S. population grew by 1.6 million from 2018 to 2019, with 38% of growth from immigration.[21] From Asia and North America mostly - https://usafacts.org/articles/where-do-us-immigrants-come-from/ https://usafacts.org/articles/where-do-us-immigrants-come-fr... In 2021, nearly 40% of immigrants, about 600,000 people, came to the US from Asia, followed by North America at 35%, Europe at 12%, Africa at 6%, and South America at just under 6%. The other 1.94% of immigrants were from Oceania or had an unknown nationality. Mexico, India, and China were the most common countries of origin for immigrants. The highest number of immigrants came from Mexico: 424,791. India followed with 202,567 people. China was third with 114,121 immigrants. TFR has been around or just below replacement rate for the last 40 years, so probably not due to that https://www.macrotrends.net/global-metrics/countries/USA/united-states/fertility-rate https://www.macrotrends.net/global-metrics/countries/USA/uni... Also, longer life expectancies.