Six years have passed since Robert Charles, a former assistant secretary of state under Colin Powell, realized that he’d spent a lifetime rubbing shoulders with an amazing cast of characters whose personal stories often possessed an uncanny power to inspire others.

Running the gamut from an eighth-grade math teacher’s selfless act of organ donation for his twin brother to Buzz Aldrin’s journey to the stars — some of these people were household names, others were not.

But the one thing they all had in common was that when the times turned tough, each of these individuals all found a way to rise to the challenge.

The other trait they all shared — and this was equally important to Charles — is that they were all Americans.

So Charles, 64, set out to write a new book, Cherish America: Stories of Courage, Character, and Kindness, that celebrates this idea of bravery and grace under fire even amid a time of division and debate in the nation.

“These are people who I think represent the best of what we as Americans are,” says Charles, an attorney and former naval intelligence officer and White House staffer for Presidents Ronald Reagan and George H. W. Bush.

“They come from the political left and the political right. None of them ever set out to become what they ended up becoming or doing. And yet they represent what we as Americans are,” Charles says. “They represent the very fabric of America.”

The 56 well-researched stories in Cherish chronicle moments of extreme challenge in the lives of soldiers, astronauts, athletes and others.

Stories, Charles insists, are the most effective, powerful tool available to convey this point.

“We don’t need another lecture,” he says. “Stories say things far better than having somebody preach or lecture at you. They get remembered and recalled when needed.”

Charles, who now runs a consulting firm in Washington, D.C., has spent his career pondering what it is that has helped set America apart despite the country’s challenges.

He says that one of his takeaways is how over the past nearly two and a half centuries, Americans — when they are performing at their very best — show they possess a certain disposition that has made almost anything possible.

“There is a special spirit that goes along with being American that goes back to our pioneer days,” he says.

“We have a certain can-do about us, a certain inner ticker, that is different from most of the rest of the world,” he continues. “Not that there aren’t people in other countries who don’t share it, but it’s a resilience and a resolve to think about the impossible, imagine it — and then go do it.”

Part of that spirit and strength, says Charles, comes from the varied demographic makeup of the U.S. population.

“Part of what’s missing today is an understanding that our differentness, our uniqueness as individuals, is not a liability,” he says. “It’s being portrayed as a liability by political parties and often by those in the media who seem to get some emotional and perhaps financial feedback from describing this differentness as a basis for division.”

But “differentness is the very basis of our genius,” Charles says.

Part of Charles’ own drive to succeed, he says, came from a handful of his early school teachers who had spent years fighting in World War II and the Korean War — and helped teach him valuable lessons about patriotism and altruism. 

One of the chapters in Cherish recounts the story of Ronald Herrick, one of Charles’ teachers, whose devotion to his brother, Richard, led to a groundbreaking organ transplant when both men were in their later 20s.

Charles knew nothing about Ronald’s powerful backstory until years later. “And that’s what makes it all the more powerful,” he says. “I just knew him as a very quiet, humble guy, full of good cheer.”

It turns out that not long after the twins returned home to Maine after serving in the Korean War, Richard’s kidneys began failing and he was given six weeks to live.

Richard’s doctor explained to Ronald that there was nothing anyone could do — but the stunned young man knew enough about the workings of the human body to ask, “I have two kidneys and I only need one. Why can’t I give Richard one of mine?”

His brother’s physician explained that it wasn’t possible because there had never been an organ transplant between two humans. Hours after that conversation, however, the doctor telephoned Ronald and, according to Charles, told him, “I’ve been thinking about this. If a transplant could ever actually work, it would need to be between identical twins.”

In the days that followed, doctors ran more than a dozen tests on the two men to try and get a better understanding of whether an organ could survive in another person’s body and came away convinced that it was worth the gamble.

When Richard protested, telling his brother, “I don’t want to put your life at risk because of me,” Charles says that his sibling replied, “We’re not going to discuss this again. We’re doing it.”

And so, in a Boston hospital in December 1954, Ronald’s kidney was successfully transplanted into his ailing brother’s body, essentially saving his life and earning his doctor a Nobel Prize.

Richard lived for about eight more years, got married and had two children.

Another story from the book that Charles describes as “emblematic of the American can-do attitude exhibited when the chips are down” comes from a series of interviews he did with Aldrin, his longtime friend, about how Aldrin and fellow astronaut Neil Armstrong almost didn’t make it back to Earth from their historic landing on the moon.

According to Charles, shortly after the two men completed their moonwalk in July 1969, they climbed back into the Apollo 11 lunar module and Aldrin’s large backpack accidentally brushed up against a panel of circuit breakers, snapping off the switch controlling the ascent engine that would allow the astronauts to leave the moon.

“You would have thought that we’d be on pins and needles [over the possibility of being trapped on the moon],” Charles says Aldrin told him. “But we weren’t because we had too much else to think about and do.”

Faced with the possibility of being marooned on the lunar surface for eternity — and just hours away from scheduled liftoff — the two men let NASA engineers try and solve the problem and took a five-hour nap.

When they awoke, the engineers still hadn’t figured out how to activate the switch. That’s when Aldrin remembered that he’d snuck a felt-tip pen onto the flight because, as he told Charles, “I liked the way it made big fat marks on our checklists.”

The reason this was so important is because the pen had a plastic casing on it that didn’t conduct electricity, allowing Aldrin to push it through the circuit panel and depress the ascent engine switch without shorting out the electrical system: “We went through the countdown and when they said, ‘Ignition,’ I used the felt-tip pen to push in the circuit breaker and we got off the moon.”

Aldrin — who flew 66 missions as a combat pilot in the Korean War and shot down two MiG-15 aircraft — told Charles that he never discussed their near catastrophe with Armstrong.  

“Buzz told me, ‘Fighter pilots don’t really do that. If you’ve been in a dog fight and almost don’t make it, you don’t think about what might have happened,’ ” Charles says. “‘We just always believed that we could get ourselves out of most problems. What happened on Apollo 11 was a little different, but we always just believed that if a problem was presented to us up there, we could figure out a solution.’ ”

It’s these qualities of inner confidence and a refusal to accept defeat — exhibited by Aldrin and all the other men and women whose stories Charles recounts in Cherish — that he believes deserve a special spotlight.

“There’s no reason that we can’t have greater days ahead and that our influence in the world can’t continue to be enormously positive,” Charles says. “There’s no reason why we shouldn’t keep looking forward with optimism. And the way we get there is to stop indulging in cynicism, to stop indulging in the idea that we benefit by pushing some of our neighbors down. Optimism, like Colin Powell used to say, is an almost limitless force multiplier.”

Johnny Dodd is a senior writer at PEOPLE, who primarily focuses on human interest, crime and sports stories. For more than two decades he has covered some of pop culture’s biggest, most-tragic and most-talked-about stories—and interviewed a staggering assortment of A-list celebrities, extraordinary everyday people, thugs and even the occasional heroic family pet. Johnny has appeared on “The Today Show,” “CNN,” “Extra!” and numerous episodes of Investigation Discovery’s “PEOPLE Magazine Investigates.” He has also written three non-fiction books that have been translated into numerous foreign languages. Johnny’s work over the years has earned over a dozen regional and national journalism awards, including a Hearst Fellowship.