New Orleans Mayor Mitch Landrieu is seeking to remove the 60-foot tall monument to Confederate General Robert E. Lee in his city. (Jonathan Bachman/Reuters)

Born in 1821 in South Carolina, James Longstreet graduated from West Point in 1842 and served with distinction in the Mexican War. As the officer corps split along sectional lines, he joined the Confederacy in 1861, eventually rising to join Gen. Robert E. Lee’s inner circle.

But it was after Appomattox that Longstreet truly distinguished himself — as the rare ex-Rebel to accept the South’s defeat, and its consequences. He urged fellow white Southerners to support the federal government and help rebuild their region on the basis of greater racial equality. He joined Abraham Lincoln’s Republican Party.

In the 1870s, he commanded a biracial state militia loyal to Louisiana’s Reconstruction government, aggravating an old war wound while fighting alongside his troops against violent white supremacists in the streets of New Orleans.

Today, this illustrious American is famous only to Civil War buffs. He remains obscure, even as the country struggles anew with the legacy of the Civil War and Reconstruction — from the removal of the Confederate battle flag at South Carolina’s state capitol, to this week’s flap over Hillary Clinton’s remark implying Lincoln’s successors were too “rancorous” toward the defeated South.

Yet ending Longstreet’s obscurity, and properly honoring him, can and should be a part of the discussion. Indeed, it’s hard to imagine a full and fair reckoning with the past in which such a personality gets no more than a footnote.

The historical-reckoning hot spot at the moment is New Orleans, where the Democratic mayor, Mitch Landrieu, and the city council have decided to remove four monuments on public property honoring Confederates or, in one case, Reconstruction-era white supremacists.

On Tuesday, a federal judge ruled against various groups trying to preserve the monuments, which include a 12-foot statue of Lee, atop a 60-foot Doric column, that has towered over a downtown traffic circle since 1884.

This is not uncomplicated; a case can be made that such statuary has been around so long that it has itself acquired educational value in the great outdoor museum that is the Crescent City.

Yet Landrieu emotionally, and accurately, argued that the Lee statue and the others had been built not as historical landmarks, but as ideological devices. They were integral to past efforts by Southern white supremacists to “put the ‘lost cause’ of the Confederacy on a pedestal.”

Nor were Southern apologetics confined to the South; by the middle of the 20th century, mainstream academic consensus held that Reconstruction had been a misguided project that collapsed due not to white Southern resistance, often violent, but to a purportedly vindictive and extreme federal government led by “radical” Republicans.

This is the tale that high school textbooks still told until historians revised it during the civil rights movement — and which Clinton, probably unthinkingly, fished out of her 68-year-old memory. Under fire from journalist Ta-Nehisi Coates and others, her team issued a follow-up statement more reflective of historical truth and, the campaign said, her own beliefs.

Longstreet played a key part in the Lost Cause myth — as villain. White ex-Confederates could never forgive his postwar racial and political treason, so they set about tarnishing his wartime military record.

In particular, they scapegoated Longstreet for the Rebel defeat at Gettysburg, though the true story was complex and included the fact that Longstreet warned Lee, in vain, not to attempt the disastrous Pickett’s Charge.

Longstreet had to be smeared so Lee could occupy his pedestal — metaphorically and, in New Orleans and elsewhere, literally. As it happens, one monument that the city proposes to remove celebrates the very same white supremacist uprising against which Longstreet commanded African American militia on Sept. 14, 1874.

Ostracized by former comrades, Longstreet died in 1904 in Gainesville, Ga.; the large block on his grave there was the only monument to him until supporters managed to get a modest equestrian statue installed at the Gettysburg battlefield in 1998, along with plaques recording his Confederate military service (not his postwar activity in New Orleans).

If New Orleans, and the country, wants to correct the balance of honor in public spaces, it will have to do more than subtract Lee and company. We should also repopulate cityscapes with underappreciated Civil War-era figures such as Longstreet, whose Reconstruction-era service has never properly been recognized.

Here’s a thought: If and when New Orleans does take Robert E. Lee off that pedestal, it should put a statue of Longstreet on it.

The James Longstreet Monument would not only help make certain specific points about what really happened in the 19th century, it would also prompt reflection on broader truths.

Longstreet risked his life for the worst cause Americans ever espoused, then for the best one. In short, he epitomized this nation’s saving grace, and humanity’s: the capacity to learn from our mistakes, and to change.

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