Our country’s educational system got its report card last week, and it wasn’t encouraging. In this year’s Nation’s Report Card, an index of student achievement in eight academic subjects, American students of all ages fell even further behind in several important areas. In mathematics, for instance, fourth and eighth graders scored worse than they did two years ago, with only 40 percent of fourth graders and 33 percent of eighth graders reaching grade-level proficiency. In reading, eighth graders took a significant step backward, with only one in three students at proficiency.

These results set off a flurry of recent press reports — and certainly, the concern is warranted. Reading and math are fundamental skills that our students need to learn, and the fact that so few of them are succeeding signals a genuine crisis.

Also discouraging are the findings about American history, showing students scoring worse in American history than any other subject — at every grade level and often overwhelmingly so.

Just how far behind are our students when it comes to learning American history? Just 20 percent of fourth-graders, 17 percent of eighth-graders and 12 percent of twelfth-graders are at grade-level proficiency in the subject.

This lack of knowledge goes to the very basics. Only one in three fourth-graders can identify the purpose of the Declaration of Independence. Fewer than half understand why George Washington was an important leader in American history. And most fourth-graders don’t know why the Pilgrims left England.

At first, it might not be obvious why our failure to teach American history should be at least as concerning as our students’ shortcomings in mathematics and reading. In fact, this challenge goes to the very heart of who we are as a country. If our children fail to learn our American history, including our founding principles and values, they fail to learn what it means to be American. And if we fail to pass this understanding on to entire generations of students, we risk losing the ideas that have made America such an exceptional nation.

How will generations of Americans who never learn the importance of the Declaration of Independence and its promise of “life, liberty, and the pursuit of happiness,” or cannot appreciate the genius of our constitutionally limited government, ever hope to preserve our heritage in the future?

This is why the findings of our Nation’s Report Card should be a call to action — to fix not only math and reading programs, but also to restore a robust American history program in our schools. If we fail to do so, we risk allowing our shared understanding of what it means to be American to disappear.

At a time when only 12 percent of twelfth graders are proficient in American history, each of us has a responsibility to share the stories about our nation’s past with the young people in our lives. And as with many subjects, the effort to inspire a passion for our history should begin early.

It is in this spirit that I have written a series of bestselling children’s books to help young people learn American history with Ellis the Elephant. Ellis learns about American Exceptionalism, Colonial America, the American Revolution, the Lewis and Clark Expedition, and much more. In my latest book, Christmas in America, Ellis discovers the joy of Christmas and how this special holiday has been celebrated throughout our nation’s history.

Visits to historic sites like George Washington’s home at Mount Vernon or Independence Hall in Philadelphia are also wonderful ways to inspire a love for American history. And of course, interactive online courses, television programs like Liberty’s Kids, and educational games like Oregon Trail can teach important history lessons too.

There are many things we hope American students will take from our educational system: the ability to read and write well, the capacity to think clearly, and the foundational knowledge that will serve them well throughout their lives. Surely, in a nation devoted to the self-government of free people, a strong appreciation of where we’ve come from and how we’ve gotten here is crucial. All of us who care about our country’s future must work to promote an understanding of its past.