All U.S. population growth in 2022-2023 happened because of immigration, not births — the first time that’s occurred since 1850, a migration think tank reported Wednesday.

That immigration growth has happened as U.S. birth rates have fallen, the Migration Policy Institute reported as part of its latest edition of “Frequently Requested Statistics on Immigrants and Immigration in the United States.”

The immigrant population grew by 1.6 million people between 2022 and 2023, reaching a record high of 47.8 million in 2023, according to the analysis. That’s about a 3.6% population increase, the largest annual growth since 2010, the institute stated in its report.

However, the foreign-born percentage of the U.S. population is 14.3%. That puts it slightly below the 14.8% registered in 1890, MPI said.

Nearly three-quarters (73%) of immigrants in the U.S. are legally present and almost half are naturalized citizens, according to MPI.

In addition to naturalized citizenship, those with legal status include green-card holders (legal permanent residents), refugees, those who have been granted asylum, had long-term visas as students, temporary workers or other categories.

U.S. birth rates reached a historic low in 2023, falling 2% from the previous year, according to the Centers for Disease Control and Prevention. The fertility rate fell to 54.5 birth per 1,000 females of ages 15-44 in 2023, down from 56 in 2022.

The Census Bureau began collecting nativity data in 1850, when 2.2 million immigrants made up 10% of the U.S. population.

The U.S. is in the midst of a major immigration policy shake-up, with the Trump administration making a number of moves to curtail it. Many of its efforts are focused on illegal immigration, but some legal immigration and naturalization programs and pathways are also being affected.