Washington Teen-agers and children make up a significant share of the country's multiracial population, 2000 census results show, pointing toward a trend of growing diversity in coming decades.
In at least 10 states, the percentage of multiracial residents who are of school age between 5 and 17 is at least 25 percent.
That percentage is higher than for Americans as a whole, regardless of racial background nationally, 19 percent are school age.
"The world is changing and blending. The numbers are a logical consequence of this," said George Bailey, of Oak Park, Ill. He is black, his wife is white, and they adopted two children whose biological parents are also black and white.
Society grew more accepting of interracial relationships and families during the 1990s, said Dowell Myers, professor of urban demography at the University of Southern California. The 2000 census itself was the first to give people the option of checking off more than one race.
The figures are the first detailed age breakdowns by race and ethnicity. They are part of the latest state-by-state release of detailed data covering topics asked on all census forms.
Nationally, just over 2 percent, or 6.8 million of the country's 281 million people, identified with more than one race. Of the 6.8 million, 42 percent, or about 2.9 million, were under 18.