Don't know much about history. Nope, we really don't.

Because of the rapid decline of Americans' knowledge of their own history, there is reason to worry that by 2026 — the 250th anniversary of the Declaration of Independence — precious few citizens will know or care why July 4th is a star-spangled national holiday.

Refusing to accept viral ignorance as inevitable, the Citizenship First project at Harlem-based Democracy Prep, a high-performing urban charter school that specializes in preparing students for active citizenship, has resolved that by the time no more than 13 more Independence Days have gone by, there will be a resurgence of civic knowledge in America.

Toward that end, Citizenship First has issued a Challenge 2026 — namely that, by the 250th anniversary, every high school graduate be able to pass the U.S. citizenship exam. That is the same test of the basics of Americanism that 97 percent of naturalized citizens currently take and pass — but which most U.S. high school students have flunked in research samplings.

Most test items are not especially challenging — for instance, naming one right or freedom from the First Amendment or correctly identifying the first 10 amendments to the Constitution as the Bill of Rights. One item asking why the colonists fought the British does require test-takers to understand that our Revolutionary forbears had multiple motivations, as Thomas Jefferson laid out so brilliantly in the Declaration of Independence.

As part of a family observance of this Independence Day, why not be daring and have each member of the family take a 20-item version of the U.S. Citizenship Exam? It is available at citizenshipfirst.us/exam.

If the exam's content proves to be foreign to resident children, families will know it is time to turn off the TV and have American history readings in the living room — and also high time to visit the school board to work for the restoration of history in the core curriculum.

Our current focus on math and English in public schools has real value but has often come at the expense of teaching American history and civics. After all, preparing the young for self-government is a founding mission of American public education.

Unfortunately, comic relief cannot endure at morning's light, given the stark reality that barely one in 10 American high school students scored proficient in their grasp of U.S. history on the most recent National Assessment of Educational Progress, published in 2011.

Nor is it funny that more than one-third of high school seniors — including an astounding 62 percent of black and 50 percent of Hispanic students — scored "below basic" on the NAEP civics test, with basic being the most bare-bones level of competence.

Another sad piece of recent news is that future NAEP testing of history and civics is being cut back severely, as a result of a misguided bureaucratic choice among many possible spending cuts to meet the demands of sequestration. Americans need more data, not less, about how much their young are learning, or not learning, about their common heritage and responsibilities as free citizens.

There are many reasons Americans don't know much about history — or civics. A short explanation is that the education establishment no longer values these as serious disciplines.

A recent 50-state Lexington Institute study found that few states any longer give even lip service to the idea that a university major in history ought to be a requirement for teaching high-school history. A great many state certifiers of history teachers allow a wide array of alternatives that sometimes omit U.S. history entirely.