'We're raising young people who are, by and large, historically illiterate," David McCullough tells me on a recent afternoon in a quiet meeting room at the Boston Public Library. Having lectured at more than 100 colleges and universities over the past 25 years, he says, "I know how much these young people—even at the most esteemed institutions of higher learning—don't know." Slowly, he shakes his head in dismay. "It's shocking."

He's right. This week, the Department of Education released the 2010 National Assessment of Educational Progress, which found that only 12% of high-school seniors have a firm grasp of our nation's history. And consider: Just 2% of those students understand the significance of Brown v. Board of Education....

The 77-year-old author has been doing his part—he's written nine books over the last four decades, including his most recent, "The Greater Journey: Americans in Paris," a story of young Americans who studied in a culturally dominant France in the 19th century to perfect their talents. He's won two Pulitzer Prizes, two National Book Awards and the Presidential Medal of Freedom, the nation's highest civilian award.

"History is a source of strength," he says. "It sets higher standards for all of us." But helping to ensure that the next generation measures up, he says, will be a daunting task....