For the first time in the history of the United States, more children were born to ethnic minorities last year than to white families, new data has shown, highlighting a seismic shift in the demographic complexion of America.

The passing of the long-anticipated milestone marks a tipping point for a country that was founded by white European settlers, wrestled with slavery and civil rights, but is now looking at a future where prosperity will lie increasingly in the hands of young Hispanics, African-Americans and Asians.

The data from the U.S. Census Bureau starkly illustrated the social, racial and economic divisions that wrack modern America, as an aging band of white baby-boomers is asked to pay taxes to fund the education and welfare of an ethnically diverse younger population.

The figures showed that in the year to July 2011, 50.4 per cent of babies born in the U.S. were born to non-whites - 26 per cent for Hispanics, 15 per cent African-Americans, 5 per cent Asian and the remaining 4.5 per cent in mixed marriages.

And while whites - currently 63.4 per cent - are projected to remain a majority of the U.S. population until 2050, they will form a dramatically shrinking part of the working-age population who will pay taxes and sustain economic growth.

Although a weak U.S. economy has slowed Hispanic immigration in recent years, the demographic momentum is firmly with minorities, with white U.S. women now having a median age of 42, compared with just 27 for Hispanics, the peak age for fertility.

"These babies are soon to be filling up our schools, and in a generation filling up our labour force and transforming the U.S. population as a whole," said Mark Mather, a demographer with the Population Reference Bureau in Washington. "It's really children who are at the forefront of racial and ethnic change in the United States. There's a huge gap in the racial-ethnic composition of the children in the U.S. compared with older adults, who are mostly white."

Sociologists warn that failure to invest in the education of minorities - who are more likely to drop out of school and less likely to get a university degree than whites - could have a catastrophic effect on the competitiveness of a workforce already under pressure from the emerging Asian economies of China and India.

However, Roderick Harrison, a sociologist at Howard University and former chief racial statistician at the U.S. Census Bureau, said that the deep polarization of U.S. politics was making it almost impossible to address issues that were of increasingly importance to the U.S..

"The country is close to ungovernable and this is something that is just getting to be beyond us," he said, "There are more benefits for political parties to exploit these divisions for short-term gain than to work for an overall solution that would require compromises, but would put the country on the right course. I don't see very much hope."

Political analysts said the U.S. faced the challenge of sketching out a "social compact" that could lay the foundations for prosperity and would require both demographic elements - older whites, younger ethnic minorities - to invest in each other.

Jamal Simmons, a Democratic political consultant and race-relations expert, said: "In years to come, those younger, browner people are going to have to pay for the retirement costs of those older, white ones. There is a social compact here - that both groups need to look out for each other. It will be impossible for that younger, browner generation to provide for their elders if they don't have the education and economic ability to generate a growing economy."

The use of vouchers to opt out of the public education system and the row over the Obama health care reforms, Mr Simmons added, were both examples of where the ethnic and socio-economic battle for America is being joined.

Conquering such challenges will test America's ability to renew itself, said Professor William Frey, a senior fellow at the Brookings Institution. He said it would take political and civic leadership "so that you don't just get fanning of the flames and resentment of immigrants to win votes".

He added: "The argument can be made - we are a nation of immigrants after all."