In a speech spanning two days in May 1856, Massachusetts Senator Charles Sumner spent five hours on the floor of the Old Senate Chamber denouncing the Kansas-Nebraska Act, a compromise bill that left the fate of slavery in those territories to be decided by local popular vote. In the course of his remarks, Sumner called Illinois Senator Stephen Douglas, chief architect of the act, a “noise-some, squat, and nameless animal.” He described Andrew Butler of South Carolina, a leading supporter of the act, as so desperate for “the harlot, Slavery,” that he “discharged the loose expectoration of his speech” at the very thought of embracing her—an allusion to the fact that Butler was known to lisp and drool.

Two days later, on May 22, while Sumner sat at his desk preparing copies of his speech to be mailed around the country, a second cousin of Butler’s, Representative Preston Brooks of South Carolina, entered the Senate chamber. After waiting for the last female spectator to leave the visitors’ gallery, Brooks approached the Massachusetts senator, told him that he had read his words with “as much impartiality as was possible,” and then beat him over the head with a walking stick made of gutta-percha—the same hard material still used today to fill the excavated root canals of infected teeth. Sumner collapsed in a pool of blood and, in the days that followed, nearly died.

Many historians have described this assault as the moment when all pretense of civility between North and South broke down and the question of civil war became a matter of when rather than if. The Yale historian Joanne Freeman now casts doubt on the singularity of the event in a revealing new book, The Field of Blood, which takes its title from a commiserating letter sent to Sumner by a friend. Between 1830 and 1860, Freeman reports, “at least eighty violent incidents between congressmen in the House and Senate chambers or on nearby streets and dueling grounds” took place. The caning of Sumner was just one attack in a long tradition of mayhem on Capitol Hill, or what Freeman calls “the ongoing Congressional floor show” of verbal abuse and violence. The Civil War scholar David Potter wrote long ago that, by the 1840s, “Congress was beginning to lose its character as a meeting place for working out problems and to become a cockpit in which rival groups could match their best fighters against one another.” Freeman discloses a surprising amount of literal truth in Potter’s metaphor.

The Field of Blood is an impressive feat of research in the face of recalcitrant sources. For one thing, early Washington newspapers depended on government printing contracts—and so, lest they offend their patrons, they offered a sanitized view of what went on in Congress. Over the first three decades of the 19th century, the National Intelligencer and later the Congressional Globe, published detailed reports of congressional debates. But Freeman points out that lawmakers were allowed to make revisions before publication, so what readers actually got were “speeches as congressmen wished they’d made them,” rather than accurate transcriptions of what they had said. Moreover, their violent behavior was obscured with glosses like “threatening exchanges” or “remarks of an unfortunately personal nature.” Freeman enumerates the facts concealed by the circumlocutions: “canings, duel negotiations and duels; shoving and fistfights; brandished pistols and bowie knives; wild melees in the House; and street fights with fists and the occasional brick.”

To unlock this rude truth behind the screen of euphemism, she turns to a manuscript diary kept by a government bureaucrat named Benjamin Brown French, a Jacksonian Democrat who arrived in Washington from New Hampshire in 1833 and rose through the (then-thin) ranks of federal employees to become clerk of the House in 1845 and commissioner of public buildings in 1853. Today, one would call him “conflict-averse.” Like his fellow New Hampshire Democrat Franklin Pierce, whom he served during Pierce’s presidential campaign in 1852, French thought that abolitionists were fanatics and worried that sectional tension over the issue of slavery threatened the ability of the federal government to go about its business. “Singing a song,” in Freeman’s words, “of Union and Jackson,” French also approved of the so-called gag rule, which tabled without debate all petitions that Congress received from constituents on the subject of slavery. By the later 1850s, however, with secessionist sentiment rising among Southern Democrats, he joined the emerging antislavery coalition of Whigs and Northern Democrats that became the Republican Party. The capstone of his career came in 1861, when he served as chief parade marshal at Lincoln’s first inauguration.

For the better part of 40 years, French enjoyed what Freeman calls a “ringside seat” close to the rhetorical and actual fighting in Congress. She uses his diary to good effect in describing the congressional arena as a “den of braggarts and brawlers.” Beginning with the Capitol building itself, she points out that in the original House chamber, completed in 1807, there were 145 seats representing 17 states, while over the next 50 years the number of states rose to 31 and representatives to 240. In the larger space to which the House moved in 1857, it was not unusual for the temperature to reach 100 degrees in the summer, and for the air—such as there was in a windowless room—to fill with the stench of sewage wafting up from the Capitol basement.

“With its clubby intimacy and luxurious red Moroccan leather chairs,” the Senate had a somewhat better atmosphere—but not always. Six years before Brooks brought the spirit of the House into the Senate at Sumner’s expense, Senator Henry Foote of Mississippi drew a pistol on Missouri Senator Thomas Hart Benton over the fate of California, which Foote wanted open to slavery and Benton wanted closed. Benton jumped to his feet, ripped open his jacket to bare his chest, and dared Foote to fire. Cartoonists had a field day with the image of the brawny Benton taunting the scrawny Foote, who was already retreating by the time a colleague snatched his weapon away and locked it in a desk.

The picture of Congress we get from this book is less of a deliberative body of sober adults than of binge-drinking adolescents left alone without adult supervision. At first, the rowdy behavior took place within the confines of a quasi-private club, and thanks to the reticence of the early newspapers, what happened in the Capitol mostly stayed in the Capitol. But by the 1840s, with the rise of a commercially independent and increasingly partisan press, congressional brawling turned into a spectacle greeted by different factions of the public with delight or disgust. A Row in the Senate! Collision Between Foote and Benton! Pistol Drawn! was the blaring headline in the Milwaukee Sentinel and Gazette after the dustup between the two senators. Two days later, the editors of the Boston Herald wrote: “If one-half of our Congressmen would kill the other half, and then commit suicide themselves, we think the country would gain by the operation.”

By the time Brooks attacked Sumner in 1856, there was no keeping the truth about Congress under wraps. Word of the attack, carried by telegraph, reached The New York Times within 45 minutes.

In the early years, it was usually a Southerner who threw the first punch, pulled out the weapon, or—before the widespread adoption of anti-dueling laws—made the formal challenge demanding satisfaction. Following historians such as William R. Taylor (Cavalier and Yankee, 1961) and Bertram Wyatt-Brown (Southern Honor, 1982), Freeman writes that, for Southerners, “avoiding a fight could be a serious liability” for their reputation among their constituents. Northerners, by contrast, “were slower to fight than Southerners and quicker to call in the law.” But by the later 1850s, with the influx of Republicans (Thaddeus Stevens in the House, like Sumner in the Senate, was a master of invective), the culture of insult and threat, if not outright violence, in Congress had become more reciprocal.

Freeman’s story, which ranges beyond Washington, has elements of both horror and slapstick. When, in 1837, the speaker of the Arkansas House was insulted by a representative, he descended upon the offender and killed him with a bowie knife. “Acquitted for excusable homicide,” he was “reelected, only to pull his knife on another legislator during debate, though this time the sound of colleagues cocking pistols stopped him cold.” In 1856, a Southern-born California Democrat, told by a waiter at Willard’s Hotel that he’d arrived too late for breakfast, pulled out a gun and shot the man to death. Freeman doesn’t say whether the shooter stepped out elsewhere for ham and grits or waited until the dining room reopened for lunch. In Richmond, where representatives and senators from the seceded states convened a Congress of their own after Lincoln’s election, they hurled inkwells at one another over who was more loyal to the new Confederacy. The whole story has the manic oscillation between cruelty and comedy of a Marx brothers’ script.

The larger context of Freeman’s narrative is that of a political culture that’s more cruel than comic: Antebellum America was rife with shootings, stabbings, and brutality of one kind or another. “Congressional violence,” Freeman writes, “was of a piece with this world.” In the South, the regime of slavery was of course founded on violence in the form of whipping, beating, lynching, and rape—not to mention the chronic psychological violence endured by every enslaved person at every moment of life. But violence was prevalent in the North as well. In the free states, “hand to hand combat and rioting at polling places” was not unusual. Parents beat children, teachers beat students, and citizens appointed themselves vigilantes in the service of this or that cause. By the 1830s, mob action was a commonplace specter in political speeches by Whigs and Democrats alike. When John Quincy Adams, who hated slavery and fought the gag rule, wrote in his diary in 1836 that “I shall henceforth speak in the House of Representatives at the hazard of my life,” he was not being histrionic.

Journalism, too, was a dangerous business—especially for antislavery newspapers. In 1838, the Philadelphia office of The Pennsylvania Freeman, edited by the Quaker poet John Greenleaf Whittier, was trashed and burned. In 1845, proslavery thugs drove the True American, edited by Cassius Clay in Lexington, Kentucky, out of the state despite Clay’s having fortified the office with a cache of rifles and gunpowder. Elijah Lovejoy’s abolitionist paper, the Observer, was attacked three times by a mob before Lovejoy was murdered by a fourth in 1837. In 1856, after the New-York Tribune ran an article critical of Albert Rust, Democrat of Arkansas, Rust spotted the Tribune’s editor, Horace Greeley, walking on Capitol Hill, punched him in the head, and, in a mild preview of how Brooks was soon to treat Sumner, followed him to his hotel, where he struck him again, this time with his cane.

Nor did violence as a political tool belong only to the partisans of slavery. After passage of the Fugitive Slave Act in 1850, mobs in states from Ohio to Massachusetts attacked officials attempting to enforce it. In all these respects, one could say that America’s congressional representatives represented America passably well.

Freeman is too good a historian to trot out facile parallels with the present, but there is an implicit presentism throughout her book. Conceived and researched largely before the rise of Donald Trump, The Field of Blood nevertheless feels current. The political discourse it documents, if not quite (yet) the level of political violence, is alarmingly familiar in our own time, though so far members of Congress like Gabby Giffords and Steve Scalise have been attacked by enraged constituents rather than by one another.

Still, to read this book is to be disabused of the notion that there is anything unprecedented in the degraded political discourse of our own day. In 1848, after a white mob fell upon black people in the streets of Washington to avenge a failed escape attempt by a group of slaves, Senator John P. Hale of New Hampshire proposed that persons guilty of “riotous or tumultuous” behavior be held accountable—to which Mississippi’s Henry Foote responded that, if Hale would like to visit his state, he would “grace one of the tallest trees of the forest, with a rope around his neck.” In 1856, Nathaniel Banks of Massachusetts, the first Republican who served as speaker of the House, received a cordial letter calling him a “Shit ass trator tory coward” and recommending that he “Quit the US God damn you and your party if you don’t like us.”

One question that Freeman doesn’t entirely answer is whether she sees the behavior of antebellum politicians as a cause of, or a correlation with, the nation’s descent into warfare against itself. Sometimes she reproaches them for inciting violence, as when she writes that “by performing sectional warfare in the halls of Congress…they stoked the flames of disunion.” Yet the metaphor of fanning the fire, which recurs throughout the book, seems something of an evasion. Could the fire have been doused with a splash of courtesy? Would lowered voices have slowed the drift toward civil war?

At times, Freeman appears to direct some of the blame toward the press, as when she writes that “ironically, the workings of a free press enforcing congressional accountability—the very touchstone of democracy—were helping to tear the nation apart.” She certainly does not mean to call upon the press—retrospectively or prospectively—to censor itself, but one theme in the book is that the tone of public rhetoric really does matter, that violent words can provoke violent deeds—a point of grim salience at present. As for Freeman’s view of the Civil War, it’s not clear whether she sees it as an avoidable catastrophe or, in New York Senator William Henry Seward’s famous phrase, an “irrepressible conflict.” Sometimes she appears to split the difference such as when, toward the end of her book, she acknowledges that the story she tells in The Field of Blood could not have had a different outcome, while at the same time admonishing the principal figures for allowing it to happen as it did:

In a sense, America was backing its way into civil warfare. The fire-eating rhetoric, the threats and dares, the talk of bloodying the Capitol, the pervasive guns and knives, and now the group fights on the floor: they were clear signs of a nation being torn in two. They were also blunt reminders of a lack of faith in the institution of Congress, even on the part of congressmen; a body of armed legislators is a body of men with no confidence in the power or practices of their own institution. The implications of this loss of faith were profound. If the nation’s representative body couldn’t function, could the nation long survive? Where else but in Congress could the interests of America’s many regions and constituencies be addressed through debate and compromise?

It’s not quite clear whether Freeman means to say that a more mature Congress could have found some way to reconcile America’s regional differences or that those differences were so far beyond compromise that it did not matter how Congress behaved. Either way, she does seem to be signaling that dysfunction in Congress is an early warning sign of national catastrophe.

Although The Field of Blood is unsparing when it comes to describing the failure of the politicians, Freeman is relatively reticent about the intractable issue that underlay their bitterness and hatred. The “spike in congressional violence” narrated in her book coincided with a spike in racial fear concentrated in (though hardly exclusive to) the South—fear of slave rebellion, of miscegenation, of losing the whole structure of white supremacy. From the appearance of organized abolitionism in the 1830s to the rise of the Republican Party in the 1850s, Freeman depicts Southern politicians as blustering bullies trying to goad their Northern counterparts into accepting the permanence of slavery as a feature of American life. But all the shouting and swaggering and threatening seems less an expression of confidence than a cover for fear. As James Oakes has shown in his books Freedom National and The Scorpion’s Sting, the slave states felt increasingly confined, besieged, even cornered as the free states grew in population and power, so much so that slave owners dreamed of establishing an international slave-based empire—an aspiration documented in Matthew Karp’s This Vast Southern Empire. In this context, the spasms of personal aggression that Freeman discloses in The Field of Blood would seem to manifest panic on the part of people who felt their power and status ebbing away. These were people who feared—with good reason—that they were on the losing side of history.

The Field of Blood is a work of substantial historical scholarship deployed on a topic of contemporary urgency. It is about local loyalties overwhelming the national interest. It is about politicians oblivious to the destructive power of their words. It is about the breakdown of what is sometimes called “comity,” defined 50 years ago by Richard Hofstadter as that social condition wherein “contending interests have a basic minimal regard for each other” and “civility is not abandoned” between political adversaries, who realize “that a community life must be carried on after the acerbic issues of the moment have been fought over.”

Yet despite disturbing similarities between our America and the one that Freeman writes about, there are considerable differences. The political conflict of the 1850s was over the one issue in American history—slavery—on which it would seem that no amount of civility, courtesy, or compromise could have preserved common ground. Today, it remains possible to imagine measures that some future Congress could take—even on such contentious issues as economic inequality, immigration, health care, and racial disparities in treatment by the law—that could ameliorate the problems that are driving Americans apart.

The Field of Blood is both a sobering and a hopeful book. It is sobering because it reminds us of what can happen when the spirit of comity collapses under pressure from a radical reordering of the nation’s economic and social life. It is hopeful because there is still reason to believe that the anger and resentment threatening our polity today are, by comparison, not beyond redress.