In the storm of crises (covid-19, the recession, Supreme Court vacancy, etc.), it’s easy to overlook the fact that the United States is engaged in the most intensive purge ever of our common historical memory.

The removal of monuments and relics of the Confederacy, and other vestiges of slavery and national dishonor, is proceeding at an unprecedented pace and scale, historians say.

In the Washington region alone, the past three weeks have seen a vote by the Fairfax County Board of Supervisors to pull three Confederate monuments from public land; the physical removal in Charlottesville of a Confederate soldier’s statue in place for 111 years; a District panel’s recommendation to rename dozens of schools, parks and public buildings; and the disclosure that the state song, “Maryland, My Maryland,” will not be sung at the Preakness Stakes.

Since early June, 77 statues and other monuments to the Confederacy have been removed nationwide, according to Kevin M. Levin, a Boston-based Civil War historian and author. Protests over the Minneapolis police killing of George Floyd triggered the movement, which has been gaining strength since a white supremacist shot and killed nine Black churchgoers in Charleston, S.C., in 2015.

“We’ve never seen anything like this,” Levin said. As a historian, he said he was pleased that “the vast majority [of monuments] have come down after very careful deliberation among local communities.”

Much of this housecleaning is overdue, but there is a risk that it goes too far. Do we remove monuments to George Washington and Thomas Jefferson because they were enslavers? What about Franklin Roosevelt, who put Japanese Americans in internment camps? Do the achievements of Woodrow Wilson and Christopher Columbus outweigh their undeniable shortcomings?

Below are four principles to guide decisions on which statues should go and which should remain. Some that stay will require new plaques describing how complex it is to judge figures from a past era with different values. These represent my own view but are based on conversations I had with historians and others who follow the issue.

●All the Confederates must go. There’s no excuse to honor or memorialize a military uprising aimed at protecting slavery. Keep in mind that most of the statues of Jefferson Davis, Robert E. Lee and company were erected decades after the war partly to reinforce the doctrine of white supremacy.

Jalane Schmidt, a University of Virginia religion professor who has helped organize protests against Confederate monuments in Charlottesville, sees an important distinction between the legacies of Confederate leaders and those enslavers who helped lead the American Revolution.