When many Americans heard about the opening of the National 9/11 Memorial & Museum, they had two words: Too soon.

But having recently visited the controversial museum, I thought: Not soon enough.

It’s not that I have any desire to rush history or return to those dark days. But spending a few hours reliving countless tales of heroism made me long for who we were following the attacks, when empathy didn’t seem like such a quaint notion and we were all rowing together.

Just descending into the archaeological heart of the World Trade Center site is enough to transport you back to that wrenching September morning: the crushed steel, the mangled firetrucks, an elevator motor and the last column, the final beam to be removed at the end of recovery operations at ground zero.

I also felt like I had entered a different type of time capsule, one that brought me face to face with a country I scarcely recognize anymore. Who we were then versus now, when we’re so coiled to pick a fight.

Instead of relentless sadness, I found compassion, so palpable in many of the exhibits — and so missing in much of today’s discourse. There’s the story of Gerard Baptiste, FDNY Ladder Company 9, who had recently bought a beat-up motorcycle, which was parked at the firehouse. After his death in the North Tower, enthusiasts pitched in and restored the 1979 Honda, calling it a “bike of healing.”

Or the Victims Quilt, a whopping 10-by-60-foot labor of love by 500 citizens nationwide who came together to create something that would provide symbolic comfort to those in mourning.

Most of all, I lingered over the “In Memoriam” exhibition, dedicated to every one of the nearly 3,000 victims of the attacks. As I touched the screen, I touched them. Through their intimate portraits, I met new brides, master gardeners, practical jokers, doting grandparents and long-suffering Mets fans.

In these hushed and solemn halls, all our divisions — along lines of race, religion and class — evaporated. And all of the victims — whether a hedge fund manager or a housekeeper, a Harvard graduate or a high school dropout — got the same type of biography: four or five sentences.

The message was clear: Every life has value.

During the last 13 years, what happened? Why have we turned so viciously on one another? When did we start showing such disrespect that it became OK for a member of Congress to shout “you lie” at a president? How did compromise become a dirty word, morphing into a sign of spinelessness rather than civility?

This isn’t just about good manners; it’s good for the country. In our current climate, try to imagine achieving some of our finest triumphs — the polio vaccine, the space program, the interstate highway system — without a deluge of boorish behavior.

Yes, I’m painting with a broad brush, of course. Since 2001, we’ve also witnessed countless examples of selfless acts all across the country, from hurricane-ravaged New Orleans to the neighborhood soup kitchen.

But, too often, that humanity feels so fragile. A report released in June by Pew Research’s Center for the People & the Press found that we are more polarized than at any point in the last two decades. We give lip service to “community” but 25 percent to 30 percent of the 10,000 adults Pew surveyed find our political opponents so misguided that they would be “unhappy” if an immediate family member married someone from the other side. Is it any wonder that smart people don’t run for office or that young adults are too cynical to vote?

Certainly, technology has made it easier for us to scrape bottom. Social media are a crowded place these days, requiring combatants to be increasingly outrageous. Anxiety — not answers — gets you trending on Twitter. Think Donald Trump’s view that doctors who help fight Ebola “must suffer the consequences.”

Events of the summer — the minimum wage debate, the immigration crisis and the unrest in Ferguson, Mo. — have exposed a particularly vile side of America.

But one cannot spend any time in that somber place in lower Manhattan without realizing that there is enough hatred of Americans in the world without Americans constantly sniping at each other.

As we go into the midterm elections, let’s use this anniversary to change the corrosive narrative. What better tribute to the 9/11 victims than tuning out the static, tuning up our national character and carrying ourselves with just a little more dignity.

Bonnie Miller Rubin writes for the Chicago Tribune. Email at [email protected] This column was distributed by MCT Information Services.