When President Obama gave a eulogy for Rev. Clementa Pinckney last Friday, he urged us all to reflect on history as we work to build a more just society:

Reverend Pinckney once said, “Across the South, we have a deep appreciation of history — we haven’t always had a deep appreciation of each other’s history.”  What is true in the South is true for America.  Clem understood that justice grows out of recognition of ourselves in each other.  That my liberty depends on you being free, too.  That history can’t be a sword to justify injustice, or a shield against progress, but must be a manual for how to avoid repeating the mistakes of the past — how to break the cycle.  A roadway toward a better world.  He knew that the path of grace involves an open mind — but, more importantly, an open heart.

If understanding history is the best way to break the cycle of injustice, we have a lot of learning to do. “Very few people in this country have any awareness of just how expansive and how debilitating and destructive America’s history of slavery is,” says Bryan Stevenson, executive director of the Equal Justice Initiative. “And so we are very confused when we start talking about race in this country because we think that things are ‘of the past’ because we don’t understand what these things really are, that narrative of racial difference that was created during slavery that resulted in terrorism and lynching, that humiliated, belittled and burdened African Americans throughout most of the 20th century.”

The South’s history of racially motivated terrorism and lynching, after all, was barely understood even as it unfolded. Journalist Ida B. Wells dedicated much of her career to documenting and raising awareness of lynching; in an 1893 speech, she lamented “lynch law” and expressed her conviction that “the apathy and indifference which so largely obtains regarding mob rule is other than the result of ignorance of the true situation.” Nearly 4,000 people were lynched between 1877 and 1950, and we only have that information because of the work of researchers, journalists, and advocates from Ida B. Wells to Bryan Stevenson. We’re still trying to expand knowledge of the true situation.

Even slavery is subject to persistent misconceptions. Margaret Biser, who spent years leading tours of a historic Southern home and plantation, wrote at Vox earlier this week about the ways people talk about slavery. They imply that many enslaved people didn’t have it so bad, that they were well taken care of, and often question whether they might have been grateful or loyal to slaveholders. “Folks have not always been taught that slavery was much more than just difficult labor: It was violence, assault, family separation, fear,” says Biser. These misconceptions are rooted in the rationalizations that slaveholders developed to establishing and maintain American slavery from its inception. As Ta-Nehisi Coates explains, “at $3.5 billion, the four million enslaved African Americans in the South represented the country’s greatest financial asset,” and slaveholders believed that black slavery, rather than contradicting ideals of equality, actually enabled white equality. Coates quotes Jefferson Davis:

You too know, that among us, white men have an equality resulting from a presence of a lower caste, which cannot exist where white men fill the position here occupied by the servile race. The mechanic who comes among us, employing the less intellectual labor of the African, takes the position which only a master-workman occupies where all the mechanics are white, and therefore it is that our mechanics hold their position of absolute equality among us.

We have to understand this past, of how we built and maintain the narrative of racial difference, not as a footnote or blunder in an otherwise admirable advancement of American society, but as woven deeply into the fabric of our social and economic structures. When we acknowledge that, it’s not entirely surprising that nine black Americans were massacred in their church in 2015, that there are 784 known hate groups in the US, or that white Americans, and particularly white Southerners, harbor unconscious negative bias toward black people. It’s not surprising that middle-income black families live in neighborhoods that are lower income than those of low-income white families, nor that in Mecklenburg County (Charlotte), NC, a place with some of the lowest economic mobility in the nation, 49 percent of black children are in high-poverty schools, compared to only 6 percent of white children. It’s not surprising that the median net worth of white households is 13 times greater than that of black households and 10 times greater than that of Hispanic households and this racial wealth gap persists even when income and educational attainment levels are the same. And it’s not surprising that our recent history includes redlining that destroyed the value of homes in black neighborhoods, urban renewal projects that fragmented and displaced black communities, mass incarceration that criminalizes large segments of generations of men of color, and predatory home-ownership and banking practices that target people of color as they begin to build wealth.

Once we understand that history, we may not be surprised by continued racial disparities, but we must be outraged by them. South Carolina State Senator Paul Thurmond—someone with his own legacy to understand and reconcile—stood and spoke of the “true situation” last week:

It is time to acknowledge our past, atone for our sins, and work for a better future. That future cannot be built on symbols of war, hate, and divisiveness.

It is time to build that “roadway to a better world” and get on the road—even if it’s slow going and full of uncomfortable conversations; even if it means accepting responsibility for past injustice and opening our minds to hard realities. It’s the only way we’ll get there.