Primary schools are celebrating a dramatic improvement in the reading and maths scores of black and Hispanic primary pupils.
Policies such as focusing on early childhood education, literacy strategies and targeting resources at schools serving needy pupils are being credited for narrowing the achievement gap between minority and white pupils.
The gap between the reading scores of black nine-year-olds and their white classmates has dropped from 35 points (on a scale of 500) to 26 in five years, says the latest five-yearly report on US testing trends. Hispanic nine-year-olds have cut the gap in maths with white pupils from 26 points to 18.
Ten points is equivalent to one year's progress on average, said the US education department.
The narrowing of the gap has come in a period when the scores of nine-year-olds of all races have been improving at the fastest rate since the US-wide National Assessment of Educational Progress tests were introduced more than 30 years ago.
Older minority pupils made more modest gains on their white cohorts. The scores, released earlier this month, show a narrowing of the academic gap between poor (mostly minority) students and their richer (typically white) peers since the late 1990s.
The gap had widened in the 1990s, reversing progress made in the 1970s and 1980s, according to Geoffrey Borman, associate education professor at the University of Wisconsin.
Despite the gains, Darvin Winick, chairman of NAEP's governing board, warned that the gap remains "too large".
NAEP tests are done by nine, 13 and 17-year-olds at a sample of 28,000 schools. The questions have remained largely unchanged since the tests started, so give a good picture of long-term progress. But the ethnic make-up of children has shifted radically. Hispanic immigrants now represent 14 per cent of students, up from 5 per cent in 1975.
The White House claimed the gains were a result of its No Child Left Behind reforms.
However, Professor Borman credited policies that started in the late 1990s.
These included a stress on literacy; a focus on phonics in reading instruction, shown to be effective with disadvantaged students; and the national nursery school scheme Head Start.
Over the past three years the No Child Left Behind reforms built on these approaches, creating a $1bn (pound;570m) literacy drive, targeting reading grants at underprivileged schools, and making schools focus on minorities or face sanctions.
New York University education professor Diane Ravitch, assistant education secretary under the first President Bush, credited the 2002 legislation with inculcating "expectations that all students meet the same standards".
But stagnant results among 17-year-olds highlighted the neglect of secondary schools in recent reforms, said Charles Smith of NAEP's governing board.