The United States has reached a historic tipping point, with children born to Latino, Asian, African American and mixed-race parents now constituting a majority of all births, the Census Bureau reported Thursday.

The long-expected demographic shift is considered a milestone for the nation, though one that California passed three decades ago when births to racial and ethnic minorities surpassed those to white parents.

The new report shows that minorities accounted for about 2 million, or 50.4%, of U.S. births in the 12 months ending July 1 of last year. Non-Hispanic whites represented 49.6% of births during the same period.

When the 2010 census was taken, minorities accounted for 49.5% of the nation’s births.

“Anyone who has been to a community center or playground recently can see that the country is changing,” William Frey, senior demographer at the Brookings Institution, said of the new census figures. “But this sends a message to everyone that the next several decades in this country will be different from the last.”

Frey and other demographers said the continuing changes in racial makeup have implications for the nation’s economy, politics and identity. A widening gap in ages between whites and minorities, for example, could affect policies and funding for Social Security, child care and health services.

Whites, now 63.4% of the total U.S. population, are expected to remain a majority for years to come and are a growing element of the older population. But the minority population is expected to continue its rise, propelled mainly by the children and grandchildren of Latino and Asian immigrants. That migration flow has begun to wane, with some reports suggesting that immigration from Mexico has reached a statistical standstill.

The Census Bureau has projected that non-Hispanic whites will become a minority by 2042, although some demographers believe that tipping point will come closer to mid-century.

California is among four states, along with the District of Columbia, where whites no longer are the majority, the new report shows. They are Hawaii (77.1% minority), the District of Columbia (64.7%), California (60.3%), New Mexico (59.8%) and Texas (55.2%).

“California has been way ahead of the game, but it’s a moment to reflect and realize that we are a multi-ethnic nation, with everything that implies,” said USC demographer Dowell Myers.

California first passed that population threshold in 1999, according to the Census Bureau. But the trend toward becoming a “majority-minority” state was apparent as early as 1985, when minority births first exceeded those of whites in California, state demographic data show.

California’s experience may hold lessons for the nation, several experts said, as its older, whiter generations wrestle with a massive state deficit and proposals for increased taxes to pay for the education of its increasingly diverse young residents.

“One of our biggest challenges in California is to do a good job of educating our diverse populations,” said Hans Johnson, a demographer with the Public Policy Institute of California.

The report shows a continued graying of America, as the nation’s median age rose slightly in 2011 to just over 37. That was even higher for non-Hispanic whites, whose median age stands at 42, with most women no longer of child-bearing age.

The Latino population is younger, with a median age of 27, with large numbers of women still within their peak years for having children. Between 2000 and 2010, there were more Latino births in the U.S. than there were arriving Latino immigrants, the experts said.

In fact, minorities accounted for more than 92% of the nation’s population growth between 2000 and 2010, Frey said.

“The aging white population is not replacing itself, so the only reason we have any growth in the population today is because of Hispanic and to some extent, Asian growth,” he said. “We have a big task ahead of us, to make sure that these newcomers can make it in this country.”

Among the report’s other findings:

In all, 348, or 11%, of the nation’s counties are majority-minority.

The most populous minority in the nation remained Latinos at 52 million in 2011. Latinos were 16.7% of the total population in 2011.

Asians were the fastest-growing minority, increasing 3% to 18.2 million.

African Americans increased 1.6% to 43.9 million.

Los Angeles Times staff writer Michael Muskal also contributed to this report.

rebecca.trounson@latimes.com