It is vitally important that young Americans learn why America is unique. Unlike many nations, defined by geography, ethnicity, and language, America is a country defined by great ideals.

This means that anyone can learn to be American. And over three centuries, tens of millions have arrived on our shores to do just that. The big ideas that define America — that all men are created equal, and that we are endowed by our Creator with certain unalienable rights, including life, liberty, and the pursuit of happiness — draw many people here.

These principles are the basis of our system of government, the subject of our political debates, and at the heart of what makes America exceptional. Thankfully, most Americans still understand the importance of these ideas.

A Gallup poll in 2010 asked respondents, “Because of the United States’ history and its Constitution, do you think the U.S. has a unique character that makes it the greatest country in the world?”

80 percent of all Americans said they believed this to be true, that America is an exceptional nation, including 91 percent of Republicans, 77 percent of Independents, and 73 percent of Democrats.

Today, however, we are in danger of losing our appreciation for what makes America unique. A recent survey conducted by the Pew Research Center found that the belief in America’s greatness is much lower among younger Americans. Only 34 percent of people between the ages of 18 and 34 say they believe America is the greatest country in the world.

While this number is concerning, it shouldn’t be surprising. For two generations we have failed to teach American history. As a result, we are beginning to see our nation’s memory of the past slip away, including the values and principles upon which America was founded.

Recent results of a Department of Education’s National Assessment of Educational Progress survey suggest the size of this challenge. Just 20 percent of fourth-graders, 17 percent of eighth-graders and 12 percent of twelfth-graders are at grade-level proficiency in American history.

Only one in three fourth-graders can identify the purpose of the Declaration of Independence. Less 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.

These statistics are frightening. They indicate that we are doing a poor job of helping the next generation understand both our amazing history and the great privilege of being American.

Those of us who are proud of our country and committed to passing on the lessons of its past must find creative ways to tell the American story.

Children’s books can be a good way to introduce young people to American history. As the author of three children’s history books, I have visited classrooms across the country to share the adventures of Ellis the Elephant, my time traveling pachyderm, with four to eight year olds. Most young people I meet are eager to learn and are excited to discover our nation’s pivotal moments.

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

If we fail to share our history with young Americans, future generations will fail to understand the essence of America. An appreciation of our history is key to ensuring that America remains an exceptional nation.