SALT LAKE CITY — Nineteen years ago I was in Ms. Minnich’s high school freshman English class watching the 9/11 terrorist attacks unfold on television.

The long tails of black smoke coming from the World Trade Center’s twin towers looked like dying breaths of hastily extinguished candles. People escaping the jet-fueled infernos on the tower’s highest floors leapt into the blue morning sky, taking their own last breaths. 

The scene was more than my adolescent mind could understand, knowing only that the world I understood had been cracked open. In those first moments, as fire trucks raced to lower Manhattan while New Yorkers raced off the island, it was too early to know how wholly my life, and those of every American, would change, forever. 

“The pictures of airplanes flying into buildings, fires burning, huge huge structures collapsing have filled us with disbelief, terrible sadness, and a quiet, unyielding anger,” President George W. Bush said that evening from the Oval Office.

“America has stood down enemies before, and we will do so this time. None of us will ever forget this day, yet we go forward to defend freedom and all that is good and just in our world,” Bush closed, saying goodnight and God bless to a nation trying to imagine the previously unimaginable. 

A romantic 15-year-old high school kid watched the towers fall that morning, unaware of an inner fire it would spark.

A decade later, a military helicopter delivered me to a small military base in Kandahar City, into the center of what had been the Taliban’s heartland. It was the spring of 2011, and I was first lieutenant in the U.S. Army and had finally made it to the fight. The image of those black smoke tails in Ms. Minnich’s English class were still imprinted in my mind. 

In the 10 years it took to get to Afghanistan, I’d volunteered some in my rural Ohio community as a firefighter and emergency medical technician, traveled to Gulf Coast to help in the wake of Hurricane Katrina and in college joined the Army. Now, finally in the war, I thought I was going to help stand down the enemies Bush had talked about that unforgettable evening. 

The president’s words that September, and the images of our nation under attack, inspired a generation of Americans to do more for its country. To do more for each other. For me, the decision to begin working at the local volunteer fire department in my hometown and to later join the U.S. Army may have been reactionary (I had to do something) but now, in this moment, I feel unsettled, like there is more work to do.

The Taliban’s support of al-Qaida — the terrorist organization responsible for 9/11 — has not waned and America’s peace talks with the Afghans have frayed in the final throes of our nation’s longest war, reports journalist Stefanie Glinski for Foreign Policy. But it’s not just the loss of friends and colleagues in that war, only to see America hand over the ground gained from their sacrifices, that’s disheartening. It’s the lack of unity, civil engagement and equality in our own country (ideals that I have been guilty of not always living up to).

In January of 1838, a 28-year-old Illinois state congressman addressed the Young Men’s Lyceum of Springfield about the “perpetuation of our political institutions.” The tall, young state legislator told his audience that as Americans of the time, “we find ourselves in the peaceful possession of the fairest portion of the earth” and in a political system “conducing more essentially to the ends of civil and religious liberty.”

He then cautioned that the loss of that peaceful possession would not come at the hands of a foreign enemy, not even with “Buonaparte for a commander,” but the destructive lot of the youthful nation would come from within. 

Almost two and half decades later in spring of 1861, on the eve of the nation’s darkest moments of civil war, that same politician spoke to the union from the nation’s capital in his inaugural presidential address

“We are not enemies, but friends,” President Abraham Lincoln told the country, offering fellowship to the recently seceded Southern states. “Though passion may have strained, it must not break our bonds of affection.” 

“The mystic chords of memory, stretching from every battlefield and patriot grave to every living heart and hearthstone all over this broad land, will yet swell the chorus of the Union, when again touched, as surely they will be, by the better angels of our nature,” Lincoln closed. Four years later his faith in the union prevailed. 

Lincoln’s words — which both parties summoned during their presidential conventions last month — have remained true. Although foreign adversaries have reached America’s shores, some of our most difficult battles, those that have shaken the foundations of our democracy, have been between ourselves. 

It’s been 19 years since we promised each other that we would never forget.

In these polarized times, during these forever wars and political battles, it’s hard to believe we haven’t forgotten. I often feel no wiser than that kid in Ms. Minnich’s freshman English class. And I worry like Lincoln.

Another president, John F. Kennedy, asked us not to concern ourselves with what the United States could do for us, but what we can do for our country.

At 9 a.m. the morning of Sept. 11, United Airlines Flight 175 passenger Brian Sweeney, a former Navy pilot, called his wife Julie from an already hijacked airplane. She didn’t answer, and Brian, in the calm voice of a man who’d found peace with his fate, left a voicemail

“Jules, this is Brian — listen, I’m on an airplane that’s been hijacked. If things don’t go well, and it’s not looking good, I just want you to know I absolutely love you, I want you to do good, go have good times, same to my parents and everybody, and I just totally love you, and I’ll see you when you get there. Bye, babe. I hope I call you.” 

Three minutes later, Flight 175 flew into the south tower of World Trade Center and burst into a massive fireball. 

Brian Sweeney said he wanted us to do good. Everybody. And today we are lucky, because we are reminded that we still have the opportunity to live up to Brian’s message.