Right-wing school board members in Jefferson County, Colorado, a suburb of Denver, went revisionist on the history curriculum.  That did not go over well with the students.  Via ThinkProgress:

According to the curricula proposal, students would only be taught lessons depicting American heritage in a positive light, and effectively ban any material that could lead to dissent. Under the proposed policy, a review committee would regularly read instructional text and course syllabi to ensure that educational materials do not stray from subject matter that complies with the policy.

But students involved in the walkout contend that censored coursework actually contradicts American history and ideals. Many of them brought signs about the patriotic nature of protest, and waved American flags as they walked.

Arvada High School senior Tyrone G. Parks disagreed with the school board, and argued that protest is a crucial aspect of American history, “and everything that we’ve done is what allowed us to be at this point today. And if you take that from us, you take away everything that America was built off of.” Tori Leu, a Ralston Valley High School student, shared a similar sentiment. “I don’t think my education should be censored. We should be able to know what happened in our past.”

It looks like the students have already learned a little history: that only repressive regimes re-write history.  It’s also just a bit ironic that it’s the right-wingers who always accuse the left of trying to brainwash the students with their political agenda.