Shortly after the National Museum of African American History and Culture opened in 2016 on the National Mall, I was speaking to some patrons of a successful nonprofit about the importance of candid racial dialogue in politics and in the places we live, work and worship.

One of the participants had recently toured the museum and had a pointed question. Why, she wondered, were all the exhibits that visitors first encounter dedicated to slavery? Among other things, she was referring to a reconstructed cabin built by former slaves from Maryland and a statue of Thomas Jefferson next to a wall with the names of more than 600 people he owned. “Couldn’t the exhibits begin with more uplift?” the woman asked, arguing that Black achievement was more worthy of the spotlight. She suggested that the museum should instead usher visitors toward more positive stories right from the start, so that if someone were tired or short on time, “slavery could be optional.”

Her question was irksome, but it did not surprise me. I’d heard versions of the “Can’t we skip past slavery” question countless times before. Each time serves as another reminder that America has never had a comprehensive and widely embraced national examination of slavery and its lasting impact. Yes, there are localized efforts. But despite the centrality of slavery in our history, it is not central to the American narrative in our monuments, history books, anthems and folklore.

There is a simple reason: The United States does not yet have the stomach to look over its shoulder and stare directly at the evil on which this great country stands. That is why slavery is not well taught in our schools. That is why the battle flag of the army that tried to divide and conquer our country is still manufactured, sold and displayed with defiant pride. That is why any mention of slavery is rendered as the shameful act of a smattering of Southern plantation owners and not a sprawling economic and social framework with tentacles that stamped almost every aspect of American life.

We can read about, watch and praise documentaries and Hollywood projects about the Civil War, or read countless volumes on the abolitionist or civil rights movements. But these are all at a remove from the central horror of enslavement itself. From the kidnappings in Africa to the horrors of the Middle Passage, the beatings and the instruments of bondage, the separation of families, the culture of rape, the abuse of children, the diabolical rationalizations and crimes against humanity — no, we haven’t had that conversation. We have not had that unflinching assessment, and we are long overdue.

America experienced 246 years of slavery before it was officially ended with the passage of the 13th Amendment. That was followed by decades of legal segregation and oppression under Jim Crow, followed by a period of willful blindness and denial. A tourist from a foreign land might well conclude that the Confederacy had actually won the Civil War based on the number of monuments, buildings and boulevards still named for heroes of its defeated army. The real truth of our shared history was a casualty of that war and, like any wound left untended, the results can be catastrophic.

A full accounting of slavery is one of terror and trauma, and for decades the natural inclination was to ask, why would anyone want to claim that history? But at a moment when the United States is dangerously divided, when we are having bitter and overdue conversations about policing, inequality and voting rights, when marauders fueled by white-nationalist rhetoric can overwhelm the Capitol proudly waving the Confederate battle flag, the more important question is this: What happens if we don’t?