Population growth is slowing in most counties nationwide amid a massive drop in immigration, new U.S. Census data shows.
Why it matters: The new data offers the best look yet at how tighter immigration enforcement is affecting America's demographic makeup.
Driving the news: International migration fell in nine out of 10 U.S. counties between 2024 and 2025 compared to the prior period, the Census Bureau says.
- Other counties stayed flat.
Between the lines: That drop is hitting populous areas especially hard.
- Census Bureau demographer George M. Hayward, in a statement: "The nation's largest counties ... are often international migration hubs, gaining large numbers of international migrants and losing people that move to other parts of the country via domestic migration."
- "With fewer gains from international migration, these types of counties saw their population growth diminish or even turn into loss."
Case in point: California's Los Angeles County lost nearly 54,000 people from 2024 to 2025, down about -0.6%. (It remains the biggest U.S. county, with about 9.7 million people.)
The big picture: The U.S. overall still grew by 0.5% between 2024-25.
- But that's down from 1% over the previous period.
Nationwide natural change (births minus deaths) held steady, while international migration plummeted from about 2.8 million people to 1.3 million — about a 55% drop.
- Caveat: The Census' international migration data include both foreigners and Americans coming home from abroad, including military service members.
The other side: The fastest-growing metros overall from 2024-25 were Ocala, Fla. (+3.4%); Myrtle Beach, S.C. (+3.2%) and Spartanburg, S.C. (+2.8%).
