Poll: How important is history?

U.S. students don't know much about American history.

Just 13 percent of high school seniors who took the 2010 National Assessment of Educational Progress, called the Nation's Report Card, showed a solid grasp of the subject. Results released Tuesday showed the two other grades didn't perform much better, with just 22 percent of fourth-grade students and 18 percent of eighth-graders demonstrating proficiency.

Education  experts say a heavy focus on reading and math under the federal No Child Left Behind law in the last decade has led to lagging performance in other subjects such as history and science.