In his latest book, The American Spirit, historian David McCullough had the rare privilege of addressing a joint session of Congress in 1989.

McCullough has observed much in his 84 years, and written much more about the past in books, and the present in speeches, and what he observes, he relates in stories that make the past come alive. On this occasion, he did not disappoint as he talked about the battles John Quincy Adams engaged in in the House of Representatives after serving as diplomat, senator, secretary of state and president.

“Adams,” McCullough declares, “small, fragile, fearing no one… spoke his mind and his conscience. … To no one else in Congress are we so indebted for the establishment of the Smithsonian Institution. With Congressman Abraham Lincoln of Illinois and Thomas Corwin of Ohio, he cried out against the Mexican War, and for eight long years, almost alone, he battled the infamous Gag Rule imposed by southerners to prevent any discussion of petitions against slavery.

“Adams hated slavery, but was fighting, he said, more for the unlimited right of all citizens to have their petitions heard, whatever their cause. It was a gallant fight and he won. The Gag Rule was permanently removed.

“We must all read history,” McCullough instructs. “How can we know who we are and where we are headed if we don’t know where we have come from?”

Last Tuesday, another political figure spoke about his battles in the Senate and beyond.

Senator John McCain spoke at The National Constitution Center, an event where he was honored with the Liberty Medal, for “his lifetime of sacrifice and service.”

Much like a modern day John Quincy, McCain reflected on the past and the present in words, like McCullough, that summarize who we are and what we stand for.

“What a privilege it is to serve this big, boisterous, brawling, intemperate, striving, daring, beautiful, bountiful, brave, magnificent country. With all our flaws, all our mistakes, with all the frailties of human nature as much on display as our virtues, with all the rancor and anger of our politics, we are blessed,” McCain said.

“We are living in the land of the free, the land where anything is possible, the land of the immigrant’s dream, the land with the storied past forgotten in the rush to the imagined future, the land that repairs and reinvents itself… the land where you can go from aimless rebellion to a noble cause, and from the bottom of your class to your party’s nomination for president.

“We are blessed, and we have been a blessing to humanity in turn. The international order we helped build from the ashes of world war, and that we defend to this day, has liberated more people from tyranny and poverty than ever before in history. This wondrous land has shared its treasures and ideals and shed the blood of its finest patriots to help make another, better world. And as we did so, we made our own civilization more just, freer, more accomplished and prosperous than the America that existed when I watched my father go off to war on December 7, 1941.”

And, like John Quincy before him, McCain is unafraid to speak “his mind and his conscience.”

“To fear the world we have organized and led for three-quarters of a century, to abandon the ideals we have advanced around the globe, to refuse the obligations of international leadership and our duty to remain ‘the last best hope of earth’ for the sake of some half-baked, spurious nationalism cooked up by people who would rather find scapegoats than solve problems is as unpatriotic as an attachment to any other tired dogma of the past that Americans consigned to the ash heap of history.

“We live in a land made of ideals, not blood and soil. We are the custodians of those ideals at home, and their champion abroad. We have done great good in the world. That leadership has had its costs, but we have become incomparably powerful and wealthy as we did. We have a moral obligation to continue in our just cause, and we would bring more than shame on ourselves if we don’t. We will not thrive in a world where our leadership and ideals are absent. We wouldn’t deserve to.

“I am the luckiest guy on earth. I have served America’s cause – the cause of our security and the security of our friends, the cause of freedom and equal justice – all my adult life. I haven’t always served it well. I haven’t even always appreciated what I was serving. But among the few compensations of old age is the acuity of hindsight. I see now that I was part of something important that drew me along in its wake even when I was diverted by other interests. I was, knowingly or not, along for the ride as America made the future better than the past.

“…I’ve been inspired by the service of better patriots than me. I’ve seen Americans make sacrifices for our country and her causes and for people who were strangers to them but for our common humanity, sacrifices that were much harder than the service asked of me. And I’ve seen the good they have done, the lives they freed from tyranny and injustice, the hope they encouraged, the dreams they made achievable. …

“With all its suffering and dangers, the world still looks to the example and leadership of America to become, another, better place. What greater cause could anyone ever serve.”

McCullough writes of America’s spirit in words of inspiration: ideas, values, sacrifice, and the magnificent changes that the U.S. Congress has fashioned: Lewis and Clark; The Homestead Act; the end of slavery and child labor; the railroad system; the Panama Canal; the Interstate Highway System; the Voting Rights Act and the moon landing.

McCain speaks of that same spirit in words proactive: “the land with the storied past forgotten in the rush to the imagined future, the land that repairs and reinvents itself,” and “the cause of freedom and justice.”

And he speaks of our “moral obligation to continue our just cause,” and cautions, “We will not thrive in a world where our leadership and ideals are absent.”

McCain and McCullough remind us that each of us has a moral obligation — through our own actions — to make this country a better place than we found it; a civic duty that extends beyond one’s own self-interests, recognizing our obligation to contribute to the overall public good.

What greater cause could anyone ever serve?