If slavery remains our nation’s original sin, then the 12-year period after its demise known as Reconstruction is an ongoing national betrayal.

During Reconstruction (1865-1877), newly freed African Americans officially became Americans and were granted “equal protection of the laws.” They were legally able to be educated. Black men could vote and hold elective office. But with these gains came a horrifying backlash whose effects continue to be felt today. Just how horrific is detailed in a new report from the Equal Justice Initiative (EJI).

“Reconstruction in America: Racial Violence after the Civil War, 1865-1876” adds to EJI’s incredible research that pushes the nation to face its appalling past. “In 2015, the Equal Justice Initiative issued a new report that detailed over 4,400 documented racial terror lynchings of Black people in America between 1877 and 1950,” writes EJI founder and executive director Bryan Stevenson. “We now report that during the 12-year period of Reconstruction at least 2,000 Black women, men, and children were victims of racial terror lynchings.”

Don’t gloss over the “at least” in that sentence. As the EJI report notes, thousands more were raped, assaulted or injured in racial terror attacks in the South during Reconstruction. But the tragedy is even worse than that. “The rate of documented racial terror lynchings during Reconstruction is nearly three times greater than during the era we reported on in 2015,” the report explains. “The deadly attacks Black communities endured in the first years of freedom—and the institutions that tolerated that violence—laid a foundation for the era of racial terror lynching that followed and the segregation and inequality that endure still.”

Carol Anderson, professor of African American studies at Emory University, has a name for this: white rage.

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In her book “White Rage: The Unspoken Truth of Our Racial Divide,” Anderson lays out a troubling yet persistent pattern in American history that started during Reconstruction. For every advancement achieved by African Americans, there is an unequal and ferociously opposite reaction.

“Black people’s basic strivings for decent housing, decent schools, the right to live un-harassed have been systematically undermined and thwarted,” Anderson told me during an interview on my “Cape Up” podcast. “This incredible resilience and resolve that we supposedly embrace in the United States, we actually punish black people for being resilient. We punish them for aspiring. We punish them for believing that they are American citizens, believing that they are even human. We punish that.”

Anderson’s book lays out the horrific story. Her chapter on Reconstruction could be a CliffsNotes version of the just-released EJI report on the period. She writes about the ways in which Southern whites tried to stop the Great Migration of 6 million African Americans from the South to the North, Midwest and West between 1915 and 1970. Anderson details how school integration ushered in by the Supreme Court’s 1954 Brown v. Board of Education decision was systematically undermined by Southern states. She walks the reader through the decades-long rollback of civil rights gains that began under President Richard Nixon and picked up pace through President Ronald Reagan.

And then there was President Barack Obama, the first African American elected to the White House. “The trigger for white rage, inevitably, is black advancement. It is not the mere presence of black people that is the problem; rather, it is blackness with ambition,” Anderson writes in her book. Every step forward has been historically greeted with legal and societal slaps back. And yet, “despite all this,” Anderson continues, "a black man was elected president of the United States: the ultimate advancement, and thus the ultimate affront.”

“The hatred for Obama was so intense and so divorced from anything that he did, except being black, that it had that base, it had that fuel within white America, looking for the un-Obama,” Anderson explained during our conversation. “And who is the [ultimate] un-Obama but Donald Trump.” The Queens-born builder who made a name for himself from his eponymous glass tower in Manhattan was a terrible businessman with no government experience. And yet he succeeded.

“What [Trump] had was a kilo of pure, uncut white supremacy. He rose to the political fore on the language of birtherism, on systematically denying the legitimacy of Barack Obama to hold the presidency,” Anderson said. “Every time he looks like he’s getting in trouble, he would throw another kilo of white supremacy down on the table. So we would get Muslim bans, we would get babies in cages at the border. We would get these caravans coming full of murderers and drug thieves. We would get one doggone racist rant after the other.”

Trump’s exhortations of “LAW & ORDER” and branding as “THUGS” demonstrators protesting the police-involved killing of George Floyd in Minneapolis are just more kilos of pure, uncut white supremacy from the president.

I was fortunate to have read Anderson’s book immediately after reading Robin DiAngelo’s “White Fragility: Why It’s So Hard for White People to Talk About Racism.” If “White Fragility” pushes white Americans to see their witting and unwitting role in perpetuating white supremacy, then Anderson’s “White Rage” shows that fragility in action. And if you read these two books back to back, you will have a clearer understanding why the killings of Floyd, Ahmaud Arbery, Breonna Taylor and now Rayshard Brooks brought African Americans to the streets across the country.

The nationwide protests are another generational fight against a national betrayal that took root 154 years ago. That many of the demonstrations feature a significant presence of white protesters gives me hope that we can actually break the shameful historical cycle of punishing African Americans for insisting on full and equal citizenship, for demanding “equal protection of the laws.”

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Activist and rapper Michael "Killer Mike" Render says black Americans could "have freedom in an instant" if they plot, plan, strategize, organize and mobilize. (Joel Adrian/The Washington Post)

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