ARVADA, Colo. — A new conservative school board majority here in the Denver suburbs recently proposed a curriculum-review committee to promote patriotism, respect for authority and free enterprise and to guard against educational materials that “encourage or condone civil disorder.” In response, hundreds of students, teachers and parents gave the board their own lesson in civil disobedience.

On Tuesday, hundreds of students from high schools across the Jefferson County school district, the second largest in Colorado, streamed out of school and along busy thoroughfares, waving signs and championing the value of learning about the fractious and tumultuous chapters of American history.

“It’s gotten bad,” said Griffin Guttormsson, a junior at Arvada High School who wants to become a teacher and spent the school day soliciting honks from passing cars. “The school board is insane. You can’t erase our history. It’s not patriotic. It’s stupid.”

The student walkout came after a bitter school board election last year and months of acrimony over charter schools, teacher pay, kindergarten expansion and, now, the proposed review committee, which would evaluate Advanced Placement United States history and elementary school health classes.