Is the most violent period in American history beginning to repeat itself — stirring painful memories and unleashing ugly precedents that most Americans would like to forget, or have forgotten already?

[IMGCAP(1)]In 1856, in the midst of growing, increasingly furious and often intemperate debate over American slavery, the pro-abolition Sen. Charles Sumner, a Massachusetts Republican with a silver tongue and Brahmin snobbery to burn, took to the Senate floor to denounce a recent pro-slavery oration by a colleague, Democratic Sen. Andrew Butler of South Carolina.

As noble as was his cause, Sumner’s three-hour stem-winder featured a cruel impersonation of the elderly pro-slavery Butler, who spoke with a slur caused by a stroke. No one threw a brick at Sumner’s office, but the very next afternoon, Butler’s nephew, Democratic Rep. Preston Brooks (S.C.), avenged his uncle by entering the upper chamber and brutally attacking Sumner as he sat at his Senate desk, using a heavy gutta percha cane to beat him into unconsciousness. When horrified fellow Senators tried to intervene, Brooks’ allies forcibly restrained them, insisting that the “gentlemen” had to settle their dispute on their own (even though only one of them was armed). During the horrifying sneak attack, Sumner somehow crawled back under his desk, using his arms to shield his head from the blows, struggling so desperately to escape that he actually ripped the firmly bolted desk from the floor.

Sumner nearly died from the attack, and though he ultimately recovered, did not return to Washington for three years. His desk, reattached by Senate laborers, remained empty for about 36 months, a symbol of the Senator’s survival — and the gritty endurance of the abolitionist movement. By the end of 1856, he had become a living martyr to the cause of anti-slavery. But Preston Brooks suffered no consequences or punishment; in fact, he became a hero to the champions of Southern chivalry, racism and slavery. When news reached the South that Brooks had shattered his cane on Sumner’s head and back, admirers even flooded his office with replacements. The House never voted to censure the South Carolinian, though ultimately he resigned.

Only the press spoke out for an outraged North. Calling the incident “the ruffianly assault upon Mr. Sumner,” a New York Times reporter took pains to condemn those who cheered or excused it by insisting Brooks had meant no real harm. “The defenders of this outrage (for same, be it said, it has defenders here in creatures bearing the human form) tell us that there was no such purpose — but only a design to disgrace the Senator from Massachusetts. Paltry subterfuge! If that were the only purpose, the weapon would have been something far less dangerous to life.”

A few days later, the paper editorialized further about the appalling absence of regret from the South — an indifference that eerily presaged the current reluctance of Republican leaders to condemn a new wave of violence against legislators (and in some cases, their relatives): “There never was so good an opportunity offered to the South, before, to make capital for itself, as in this case of the ruffian Brooks; but, true to their instincts, and blinded by the madness that must lead to their utter defeat, they have chosen to defend the outrageous scoundrelism of their self-appointed champion and have thus made themselves responsible for his acts.”

It would be easy to say the violent atmosphere in Congress cooled thereafter. True, not even the widening North-South split over slavery ever erupted quite so brutally again within the confines of the Capitol. But what happened next is known to every school child (though perhaps not to tea party demonstrators too busy tweeting threats or sending faxes adorned with nooses to read their history books): secession, societal upheaval, destruction and 620,000 dead on Civil War battlefields from Texas to Pennsylvania.

Near the war’s end, another controversial politician was forced to walk the gauntlet of hostile citizenry assembled in and around the Capitol. Abraham Lincoln arrived for his second inauguration on March 4, 1865, to a mostly warm reception from supporters relieved that the rebellion was nearly crushed. But not everyone agreed that Lincoln was a hero. Lurking under the Capitol dome was a disgruntled actor, part-time Confederate agent and full-time racist named John Wilkes Booth. Startled friends accompanying Lincoln to his swearing-in that day were shocked to glimpse the famous performer inching his way along the crowd inside the Rotunda, glaring at the president menacingly. “What a wonderful opportunity I had today to shoot the president,” Booth later confided. Six weeks later, after hearing the president propose voting rights for African-Americans, he did precisely that.

Had Booth instead absorbed the poignant closing words of Lincoln’s inaugural message outside the Capitol that day, he might have heard a pacific message that still resonates in history, if not in that vast plaza today, or, sadly, within the country that Lincoln lived and died to reunite. That message was: “With malice toward none, with charity for all.” It would be far wiser for modern Americans to reread Lincoln’s words than to re-enact the war that marked his presidency.

Harold Holzer is author, co-author or editor of 35 books on Abraham Lincoln and the Civil War. He served with Sen. Dick Durbin (D-Ill.) and then-Rep. Ray LaHood (R-Ill.) as co-chairmen of the U.S. Abraham Lincoln Bicentennial Commission. In the 1970s, he was press secretary to the late Rep. Bella Abzug (D-N.Y.) and later worked in the administration of New York Gov. Mario M. Cuomo (D). His next book, with co-editor Craig L. Symonds, is “The Complete New York Times Coverage of the Civil War,” which includes the complete account of the Sumner report and editorial cited in this article.