Lee’s code of gentlemanly conduct did not seem to apply to blacks. During the Gettysburg campaign, he did nothing to stop soldiers in his army from kidnapping free black farmers for sale into slavery. In Reconstruction, Lee made it clear that he opposed political rights for the former slaves. Referring to blacks (30 percent of Virginia’s population), he told a Congressional committee that he hoped the state could be “rid of them.” Urged to condemn the Ku Klux Klan’s terrorist violence, Lee remained silent.

By the time the Civil War ended, with the Confederate president, Jefferson Davis, deeply unpopular, Lee had become the embodiment of the Southern cause. A generation later, he was a national hero. The 1890s and early 20th century witnessed the consolidation of white supremacy in the post-Reconstruction South and widespread acceptance in the North of Southern racial attitudes. A revised view of history accompanied these developments, including the triumph of what David Blight, in his influential book “Race and Reunion” (2001), calls a “reconciliationist” memory of the Civil War. The war came to be seen as a conflict in which both sides consisted of brave men fighting for noble principles — union in the case of the North, self-determination on the part of the South. This vision was reinforced by the “cult of Lincoln and Lee,” each representing the noblest features of his society, each a figure Americans of all regions could look back on with pride. The memory of Lee, this newspaper wrote in 1890, was “the possession of the American people.”

Reconciliation excised slavery from a central role in the story, and the struggle for emancipation was now seen as a minor feature of the war. The Lost Cause, a romanticized vision of the Old South and Confederacy, gained adherents throughout the country. And who symbolized the Lost Cause more fully than Lee?

This outlook was also taken up by the Southern Agrarians, a group of writers who idealized the slave South as a bastion of manly virtue in contrast to the commercialism and individualism of the industrial North. At a time when traditional values appeared to be in retreat, character trumped political outlook, and character Lee had in spades. Frank Owsley, the most prominent historian among the Agrarians, called Lee “the soldier who walked with God.” (Many early biographies directly compared Lee and Christ.) Moreover, with the influx of millions of Catholics and Jews from southern and eastern Europe alarming many Americans, Lee seemed to stand for a society where people of Anglo-Saxon stock controlled affairs.

Historians in the first decades of the 20th century offered scholarly legitimacy to this interpretation of the past, which justified the abrogation of the constitutional rights of Southern black citizens. At Columbia University, William A. Dunning and his students portrayed the granting of black suffrage during Reconstruction as a tragic mistake. The Progressive historians — Charles Beard and his disciples — taught that politics reflected the clash of class interests, not ideological differences. The Civil War, Beard wrote, should be understood as a transfer of national power from an agricultural ruling class in the South to the industrial bourgeoisie of the North; he could tell the entire story without mentioning slavery except in a footnote. In the 1920s and 1930s, a group of mostly Southern historians known as the revisionists went further, insisting that slavery was a benign institution that would have died out peacefully. A “blundering generation” of politicians had stumbled into a needless war. But the true villains, as in Lee’s 1856 letter, were the abolitionists, whose reckless agitation poisoned sectional relations. This interpretation dominated teaching throughout the country, and reached a mass audience through films like “The Birth of a Nation,” which glorified the Klan, and “Gone With the Wind,” with its romantic depiction of slavery. The South, observers quipped, had lost the war but won the battle over its history.