A total of 49.6 million children attended public and private school in 2003, beating the previous high mark of 48.7 million — set in 1970 when the baby boom generation was in school.
The growth is largely due to all the children born in the late 1940s to early 1960s, who have since become parents themselves, the Census Bureau said Wednesday. Rising immigration played a part, too.
"You could have predicted this back in 1970 when we had all those kids," said Mark Mather, a demographer for the Population Reference Bureau, which assesses population trends. "We knew they were going to have kids of their own. We have this classic echo effect going on."
Even if it isn't surprising, the record tally of students in the first 12 grades poses steep challenges for schools: recruiting teachers, helping children who don't speak English, keeping class sizes manageable and coming up with enough financial aid for college students.
In population rings outside urban areas and in Western states such as Nevada and California the growth has been concentrated, increasing demands on schools.
"They just really don't have the fiscal capacity to match this," said Scott Young, senior policy specialist in education for the National Conference of State Legislatures.
In districts outside Atlanta, Houston and Las Vegas, enrollment has soared more than 20 percent in last five years, said Bruce Hunter, who directs lobbying for the American Association of School Administrators. His group has identified more than 400 such districts.