For the first time in American history, whites no longer comprise the majority of babies being born in the United States.

The U.S. Census Bureau announced Thursday that minorities now account for 50.4 percent of all U.S. births, compared to 49.6 percent for whites. The development follows decades of increasing immigration that helped fuel a fast-growing minority population.

Officials say a key reason for the change is also the median age of the white and minority populations. The median age for U.S. whites is 42 while the median age for U.S. Hispanics is about 28, meaning many Hispanic women are still in the prime child-bearing years.

Census officials say whites still are the largest single demographic group, and that almost all ethnic groups saw a decline in the number of births, which many experts attribute to the difficult economic climate. Still, demographers say the trend is clear — the youngest generations of Americans are being raised in a culture that is dramatically more diverse than at any time in the country's history.

The Census Bureau findings are based on data collected over a 12-month period ending in July 2011.