Hispanics accounted for more than half of the U.S. population increase over the last decade, exceeding estimates in most states as they crossed a new census milestone: 50 million, or 1 in 6 Americans.
Meanwhile, more than 9 million Americans checked two or more race categories on their 2010 census forms, up 32 percent from 2000, a sign of burgeoning multiracial growth in an increasingly minority nation. The Census Bureau on Thursday released its first set of national-level findings from the 2010 count on race and migration, detailing a decade in which rapid minority growth, aging whites and the housing boom and bust were the predominant story lines.
Analysts said the results confirmed a demographic transformation under way that is upending traditional notions of racial minorities, political swing districts, even city and suburb.
"These are big demographic changes," said Mark Mather, an associate vice president at the nonprofit Population Reference Bureau.
"By 2050, we may have an entirely new system of defining ourselves," he said.
According to the data, Americans continued their decades-long migration to fast-growing parts of the Sun Belt. Their move to big states such as California and Texas as well as fast-growing Mountain West states pushed the nation's mean center of population roughly 30 miles southwest to a spot near the village of Plato, Mo.
African-Americans in search of wider spaces increasingly left big cities such as Detroit, Chicago and New York for the suburbs, typically in the South. Both Michigan and Illinois had their first declines in the black population since statehood as many of their residents opted for warmer climes in the suburbs of places such as Atlanta, Dallas and Houston.
The smaller numbers were a surprise to some city officials, including New York Mayor Michael R. Bloomberg, who questioned the census count of 8.2 million for his city and suggested immigrants may have been missed.
Multiracial Americans now make up 2.9 percent of the U.S. population, a steadily growing group -- even if it did not include President Obama, who identified himself only as African-American on his census form. Obama's mother Ann Dunham, a white woman from Kansas, married his father, the Kenyan native Barack Obama Sr.
The vast majority of multiracial Americans lived in California, Texas, New York and Hawaii. The most numerous race combinations were white-American Indian or Alaskan Native, white-black and white-"some other race."
Among census findings:
*Asians grew by 43 percent over the last decade. They were tied with Hispanics as the fastest growing demographic group. For the first time, Asians also had a larger numeric gain than African-Americans, who remained the second largest minority group at 37.7 million.
*Many of the states in the South and West that are picking up House seats due to the census count are Republican leaning, such as Texas and Florida. But most of their growth is now being driven largely by Hispanics, who tend to vote Democratic, which could put those regions in play.
*The 10 fastest-growing cities over the last decade were actually suburbs of major metropolitan areas. They included Lincoln, Calif.; Surprise, Ariz.; and Frisco, Texas, all of whose population more than tripled since 2000.