“The unintended consequence of No Child Left Behind has been to put history into an even more marginal position,” maintained Theodore K. Rabb, a professor of history at Princeton University and a founder and board member of the National Council for History Education. “It is clear that, with some notable exceptions nationwide, the amount of class time given to history, especially in the first eight grades, has been shrinking almost by the month.”

The 3-year-old No Child Left Behind Act requires annual testing in reading and math in grades 3-8 as a key measure of schools’ progress under the federal law.

In response to what they see as a rapidly growing trend, the Westlake, Ohio-based council and other groups representing teachers of history, government, economics, geography, and other social studies are mobilizing to alert policymakers and the public to their plight and build their case for a renewed focus on those subjects.

Last week alone, a national study and a state task force in Maryland highlighted the urgent challenges facing the field.

Meanwhile, the council, which represents history teachers and scholars, is circulating a statement on what it sees as “A Crisis in History.” Signed by dozens of prominent historians and educators, it calls for the infusion of more history into reading programs and instruction at large. The document is a precursor to the group’s plan for a broader campaign to raise awareness of the problem, Mr. Rabb said.

The National Council for the Social Studies, which represents 26,000 educators, has convened a group of representatives of national organizations for reading, mathematics, and science professionals to debate the use of instructional time. The NCSS’ agenda for that group also includes discussing ways to incorporate more content-area reading, the importance of a well-rounded curriculum, and strategies for getting the message to lawmakers and school administrators.

History is considered a core subject under the No Child Left Behind law, a reauthorization of the Elementary and Secondary Education Act, and is part of the “well rounded” education intended under the law, according to Michael J. Petrilli, the acting assistant deputy secretary for the U.S. Department of Education’s office of innovation and improvement.

“It is deeply distressing to hear that some schools and school districts out there are not focusing on history,” Mr. Petrilli said. “There’s nothing in the law encouraging schools to cut back on core academic subjects like history.”

The pressure on school districts to show progress under the law, however, has forced schools and teachers to make tough decisions on what to teach and how much time to devote to each subject, some scholars say.

“The desperate response of the schools to test pressure has been to excise history, science, and the arts, and replace them with still more such exercises in reading,” E.D. Hirsch Jr., the founder of the Core Knowledge Foundation, wrote in a paper criticizing the heightened focus many schools have placed on reading in order to raise achievement. “This is a futile strategy, since reading achievement depends on broad knowledge of [these subjects].”

In California, social studies instruction has been dwindling for several years in response to state accountability measures that have not required schools to report achievement in social studies for the elementary and middle grades. That trend has been exacerbated somewhat since the passage of the federal education law, said Nancy McTygue, the interim executive director of the California Social Studies Project, a state-financed agency that provides professional development and curriculum support for the state’s low-performing districts and schools.

The problem is particularly evident in low-performing schools or those with large proportions of disadvantaged students, Ms. McTygue said.

“Low-performing schools have dropped history,” she said, “choosing instead to have a three-hour block to teach a scripted reading program, in addition to two hours of math and required [physical education] classes. If a student goes to a low-performing elementary school and then a low-performing middle school, they won’t have history until they’re 15 or 16, and all they’ll have is 20th-century history.”