Estimates of the latest US census data show that children from racial and ethnic minorities now account for more than half the births in the US.
Black, Hispanic, Asian and mixed-race births made up 50.4% of new arrivals in the year ending in July 2011.
It puts non-Hispanic white births in the minority for the first time.
Sociologists believe the ongoing economic slowdown has contributed to a greater decline in birth rates among white people.
The US Census Bureau recorded 2.02 million babies born to minorities in the year to July 2011, just over half of all births, compared with 37% in 1990.
US birth rates have been declining, but the drop has been larger for white people.
The number of white births has fallen by 11.4% since 2008, compared with 3.2% for minorities, according to Kenneth Johnson, a sociologist at the University of New Hampshire.
Roderick Harrison, a former chief of racial statistics at the Census Bureau, now a sociologist at Howard University, told Associated Press: “This is an important landmark. This generation is growing up much more accustomed to diversity than its elders.”
The nation’s minority population now makes up 36.6% of the total US population.
Demographers also believe the Hispanic population boom may now have peaked.
“The Latino population is very young, which means they will continue to have a lot of births relative to the general population,” Mark Mather of the Population Reference Bureau said.
“But we’re seeing a slowdown that is likely the result of multiple factors: declining Latina birth rates combined with lower immigration levels. If both of these trends continue, they will lead to big changes down the road.”