When you enter the new National Museum of African American History and Culture, you step into an elevator going down, and through its glass walls, the years flash by, with history moving backward, to the 1400s. Campaign 2016 has often resembled that kind of journey, not moving that far into the past, of course, but far enough to a time when no thin line of civility kept American citizens from lashing out at one another — loudly, and with anger and violence.

That has been the dispiriting price of the long slog to Election Day, Donald Trump vs. Hillary Clinton, with the country collectively collapsing at the finish line. Still, it would be wise for all Americans to acknowledge that there are miles to go, and that this path is one we have traveled since the beginning, often with one side celebrating and the other deflated — a future of cooperation and compromise downright impossible to imagine.

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My recent trip to the museum — both soul-wrenching and soul-cleansing — was a reminder that 2016 brought little new to this American experiment. There has been darkness and rancor, citizens looking at fellow citizens as illegitimate and not even human, but also unlikely progress, slow and with inevitable pushback, but relentless nonetheless.

It has been hard to find hope after witnessing nose-to-nose confrontations outside political rallies, the faces as twisted as those hurling epithets and saliva in the 1957 photo — on view in the museum — of my Charlotte, North Carolina, friend, Dorothy Counts, just 15 years old then, in the stylish dress her grandmother made and walking with dignity through a scary mob on the way to integrate the city’s Harding High. She lasted just four days before the hostility and a smashed car window forced her to seek education elsewhere.

But there was light when, spurred by the experience, she spent a career helping children in need. The Harding High library is now named to honor her, and a face in that ugly 1957 crowd did at last apologize.

President Barack Obama and Trump did not disregard their differences at their first White House meeting. But Trump expressed admiration for the man and the president — a first. And Obama pledged to ease his successor’s way into the most powerful job in the world, for the country’s sake.

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Will Trump seek the president’s counsel, as he said?

Perhaps he should. The museum chronicles the unlikely alliance of President Abraham Lincoln and abolitionist, author and orator Frederick Douglass. While Obama is not Douglass and Trump as Lincoln is a reach no one realistically expects, the newly elected president would do well to emulate his fellow Republican in inviting dissenting voices to the table. Lincoln, someone who doubted the ability of African-Americans to fully integrate into American society for years to come, nevertheless invited Douglass, who accepted, to the White House because their respective missions — for a president to end a Civil War, for the once-enslaved person to achieve true equality for all — required a cautious partnership, mutual respect and eventual friendship.

The tests of Trump’s statesmanship have already started. As protests of the policies and rhetoric that excited many in Trump’s base and horrified voters who opposed him spread across the country, the president elect at first reverted to form, calling them “unfair” and blaming the media. Whether someone got a hand on his Twitter account or Trump reconsidered, he had changed his tune and his opinion within hours, praising their “passion” and saying, “We will all come together and be proud!”

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As the days pass, will he criticize not only the protesters who resort to violence but some of his own voters who are committing acts of intimidation against religious and racial minorities, from scrawled graffiti on walls, cars and classroom chalk boards to physical confrontations? What was sidestepped or encouraged during the campaign season is not acceptable, and a president who wants to lead must make that clear.

What comes next depends most on citizens. As the exhibits chronicled in the museum illustrate, time and again, progress comes only with constant pressure. For those with little money or power that means unity across difference, which has been scarce, and not only during this election season.

The economic insecurity and feeling of being unloved and forgotten by the “elites” made headlines in 2016 when rural and post-industrial Americans rose up. But the urban citizens of Flint, Michigan, are still waiting for clean water. Though the two groups may disagree on whose lives matter, they are united in feeling whose lives do not to the decision-makers.

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I was lucky enough to know Franklin McCain, one of the Greensboro Four who staged an iconic sit-in at that North Carolina Woolworth store on Feb. 1, 1960. While he did not live to see his picture and the lunch counter stool in its special spot in the new museum, he talked about a moment that taught him never to stereotype.

When an older white woman put her hand on his shoulder as he sat on that stool and bent down to whisper something in his ear, he expected the worst. Then, she said: “Boys, I am so proud of you,” and told him and his companions that they should have acted years before.

For those betting against it, a visit to that museum of shared history and struggle proves the country has made it through far worse — with courage and surprising alliances. When the anger and hurt subside, it’s a trip worth taking.

Roll Call columnist Mary C. Curtis has worked at The New York Times, The Baltimore Sun and The Charlotte Observer. Follow her on Twitter @mcurtisnc3.