US population growth fell over the past decade to the second-slowest pace in history, the Census Bureau reported on April 26, after Donald Trump's tough crackdown brought immigration to a near halt.
The official 10-year count estimated that 331,449,281 million people lived in the world's third-most populous country on April 1, 2020.
That was a 7.4 per cent rise from 2010, when the official population stood at 308,745,538, the Census Bureau said.
The 10-year expansion was significantly slower than the previous decade, when the population grew by 9.7 per cent, and was barely above the record low of 7.3 per cent over 1930-1940, when the US and the world were mired in the Great Depression.
The population growth rate accelerated with the "baby boomer" birth surge after World War II, but since the early 1950s has been on a fairly steady decline.
That was only interrupted for a few years in the 1990s when millions of migrants, mostly Mexicans, entered the country without documents and stayed.
Since then, data shows the dropoff has been sharp.
In the past decade, researchers have said that the deep, year-long economic slump from the 2008 financial crisis contributed to the slowdown, with a lower birth rate and with many Mexican migrants returning to their country.
In addition, after he became president in 2017, Donald Trump sought to sharply cut legal immigration and halt illegal immigration completely.
The region showing the largest growth since 2010 was the south, followed by the west.
Arid, heavily desert Utah in the west had the fastest growing population of the 50 states, gaining 18.4 per cent, while mountainous West Virginia in the east fell by 3.2 per cent.
The Census Bureau only released the broad numbers for the country and individual states on April 26, to serve as a basis for reapportioning seats in the 435-member US House of Representatives.
In all, 13 states will either gain or lose seats, with California, the largest by population, losing one of its 53, while Texas, the second-largest, adding two to its current 36.
Others gaining one seat are Colorado, Montana, North Carolina and Oregon. Other losers were Illinois, Michigan, New York, Ohio, Pennsylvania and West Virginia.
The census was taken under a cloud of politics, with Trump trying to reverse past practice and force the agency not to count undocumented or non-citizen residents.
His push against immigration is also thought to have made many people afraid to respond to census takers.
The census was also hampered by the Covid-19 outbreak.
"Trying to count people in a global pandemic made it even more challenging," said Ron Jarmin, acting director of the Census Bureau.
The bureau plans to release details on age, race and other characteristics of the population in the coming months.