This spring, the US Congress passed a unanimous resolution condemning ISIS for its genocide against Yazidis, Christians, and Shiites. “Naming these crimes is important,” Secretary of State John Kerry said after the vote, “but what is essential is to stop them.” It’s far too late to stop the genocidal crimes committed against California Indians that Benjamin Madley chronicles in An American Genocide; nevertheless, Madley is convinced that it’s still necessary to name them.

There are several reasons for this. Scholarly studies of genocide—like actual accusations of genocide—usually steer clear of North America, and Madley wants to change that. He also writes because in a world of genocidal violence, claims of American innocence and exceptionalism are dangerous. This dire election season has featured more than the usual number of references to our traditions, values, and history, and one assumption among pundits and politicians has been that our traditions and values protect us from going over to the dark side. This is sometimes the case, but not always. When candidates summon the darker angels of our nature and call for overwhelming violence against those who kill us, threaten us, hate us, or simply annoy us, they beckon us to go where the nation has, in numerous ways, gone before.

Madley’s book is grim reading. Along with Stacey Smith, in Freedom’s Frontier, and John Mack Faragher, in his new and chilling Eternity Street, Madley is turning the history of 19th-century California decidedly noir. An American Genocide is not an elegant book, but it is a commanding one. The details—forgotten murders, massacres, and the disappearance of entire communities—sometimes bleed into one another, but there’s a purpose to the repetitiveness. It’s like watching bodies being piled on a pyre. The accumulation matters; it allows the book to make its case and avoid becoming a mere polemic.

“Genocide” is a powerful word, but one whose impact has been diminished through overuse. Madley doesn’t use the word carelessly, even though he’s writing about US policy toward American Indians, a subject that often leads people to toss the term around quite loosely. His book does not contend, as more polemical works do, that all Indian policy was genocidal. He concentrates instead on a particular place and time: California from 1846 to 1873.

Accusations of genocide in California are hardly new. Many historians, anthropologists, and Indian activists have made them, but An American Genocide stands apart for two reasons. First, Madley is interested not just in spectacular crimes, but also in their institutional basis. Second, he doesn’t use the term “genocide” for its shock value; instead, he considers the term carefully before applying it to state and federal policies.

In defining genocide, Madley relies on the criteria of the United Nations Genocide Convention, which has served as the basis for the genocide trials of defendants from Rwanda and the former Yugoslavia and has been employed at the International Criminal Court in The Hague. In the words of the UNGC, acts qualify as genocide if they are “committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group.” It is intent, not motive, that matters in establishing the fact of genocide, and the acts can include killing, causing serious bodily or mental harm, imposing conditions calculated to physically destroy the group in whole or in part, imposing measures to prevent births within the group, and forcibly transferring children of the group to others. Madley moves through several decades of California history, methodically giving examples of each and tagging the incidents like corpses in a morgue. He has also compiled nearly 200 pages of appendices detailing the killings, with sources.

Imposing the UNGC criteria for genocide on actions and policies in 19th-century California might seem anachronistic. The scholars who coined the word “genocide,” however, meant it to describe historical phenomena, including policies directed against American Indians. They were not interested in codifying modern values and retroactively applying them to the past; instead, they wanted a term that could describe a variety of actions over long periods of time. Like Gary Anderson’s recent Ethnic Cleansing and the Indian, which is about more widespread aspects of US policy toward American Indians, Madley applies a new word to an old practice. No reader of his book can seriously contend that what happened in California doesn’t meet the current definition of “genocide.” In the 19th century, Californians themselves referred to what was happening around them as “extermination”—and this was as true of those who advocated the slaughter as those who opposed it. “Extermination” amounts to a 19th-century synonym for “genocide.”

Having defined the term, Madley doesn’t focus only on the immediate perpetrators of the violence, who began their deadly work during the Gold Rush. The Gold Rush amounted to a libertarian fantasy—a society devoted solely to the pursuit of wealth. (It is a fantasy still carelessly celebrated in places like Silicon Valley.) Indians who stood in the way were dispossessed and then slaughtered. Most previous scholarship has recognized this carnage, but has tended to discuss it as the work of two groups: young men gone wild, freed from the restraint of civil authorities, and the US Army and federal government, attempting to intervene to protect Indians from American citizens.

Madley argues—and this is the core of his book—that California’s elected officials were in fact “the primary architects of annihilation,” and that they were funded and enabled by the federal government. Together, state and federal officials created what Madley describes as a “killing machine” composed of US soldiers, California militia and volunteers, and slavers and mercenaries (so-called “Indian hunters”) in it for the money. He argues that “it took sustained political will—at both the state and federal levels—to create the laws, policies, and well-funded killing machine that carried [this genocide] out and ensured its continuation over several decades.” Among those he implicates is John C. Frémont, who served as a US senator and was a Republican presidential candidate in 1856. He also indicts Leland Stanford, who was a governor of California during the Civil War, and Serranus Hastings, the state’s first chief justice.

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Madley divides the American assault on California Indians into three separate categories, all of them qualifying as genocide under the UN convention. The first was the attempt to physically exterminate tribes or the “Indian race.” In 1850, the Daily Alta California described the Gold Rush miners as united in “the work of extermination,” a term repeated in one form or another for the next 20 years. Another form of assault was enslavement and forced labor, particularly enslavement that involved the murder of parents and the capture and indenture of their children. By kidnapping children from their communities, Americans endangered both the children’s and the communities’ survival. Lastly, there were all the actions that led to widespread death from starvation and disease. Systematic violence was integral to all of these various acts of genocide—for example, the relentless attacks by federal troops, state militia, vigilantes, and mercenaries made the enslavement of Indians possible and starvation and disease inevitable.

What was so egregious about US policy was that the bar for horrifying behavior against California’s Indians was already especially low. It would have been easy to raise it, but Americans chose not to. The Spanish mission system began this work of destruction: The missions crowded often malnourished and overworked populations together, exposing them to disease. Those who ran away were hunted down, whipped, and forced to return. Sexual segregation harmed the birth rate, and large numbers of those born never reached adulthood. Madley notes the system’s horrors and the toll it took. The Mexicans, to their credit, ended the mission system. They then dissipated much of the good they had done by confiscating the mission lands and reducing many ex-neophytes—the mission Indians—to a system of peonage and forced labor. The Indians proved resilient: By the time the Americans conquered California, Indian raiders—particularly inland Miwoks and Yokuts—had put the rancheros on the defensive, threatening the very existence of Mexican California.

Madley touches only briefly on the Spanish and Mexicans, focusing instead on the Americans. As a historian, his job is to trace how things changed over time, and why. In this case, it is a gut-wrenching, nauseating task—and it poses a narrative challenge that he never fully overcomes. The killings, sometimes a few at a time, sometimes massacres of 100 or more, continued year after year for roughly a quarter of a century. Individually, they are appalling, the details hard to forget. Sally Bell, a Sinkyone woman, saw her family slaughtered before her eyes and her little sister’s heart cut out and thrown in the brush. Traumatized, she hid, reflexively clutching the bleeding heart.

I am familiar with the horrific material contained in the literature on the conflict between whites and Indians. There have been times when, appalled at the inventive cruelty of human beings, I have needed to rise from my desk and get some fresh air. Compared to the bloodshed in California, the mutual atrocities of whites and Indians in the Old Northwest that I chronicled in The Middle Ground (1991) had an odd comfort. There was a balance of horrors: By and large, this was war, and Indians meted out violence as well as received it. But in California, what Americans have often called “war” was nothing of the sort. For every American who died, 100 Indians perished. They died horribly—men, women, and children. The men who killed them were brutal. Nor did the killings result from a moment of rage; they were systematic. Reading Madley’s account of this carnage is like reading a chronicle of an abattoir, recording death after death after death. But a slaughterhouse is the wrong metaphor: The Indians were usually not transported for slaughter. Most were killed in place, shot down where soldiers, militia, vigilantes, and professional mercenaries found them.

Madley separates the killings and creates a typology to trace how and why they started and why they changed. The killers’ motives ranged from the personal to what we might call the civilizational. They included greed, fear, racism, and revenge, particularly for theft or accusations of theft. Americans killed Indians because Indians resisted their efforts to dispossess them and retaliated as best they could against acts of violence by Americans. But Americans also killed in the name of a higher cause: The killers insisted they were simply the tools of history. In 1850, the editor of the Daily Alta California articulated a common theme: The extermination of the Indians was inevitable and necessary. “Such is the destiny of that miserable race,” he wrote, “and…we are but fulfilling our own by the enactment of scenes on the Pacific similar to those which have stained with blood our Indian history…from the first dawnings of civilization.”

All of these motives were present at any given time, though the influence of each waxed and waned. Taken together, they can make the genocide seem like a kind of unquestioned conventional wisdom whose horrors appear only in hindsight. To mark this slaughter as calculated and not just the result of mass frenzy, Madley needs—and finds—“righteous gentiles.” That many Americans protested what was happening cannot redeem the irredeemable, but it does establish that with every incident of violence, there was a choice. Other people recognized and condemned the horror. It was not inevitable, and yet it went on.

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The initial American motive for slaughter arose in the first months of the conquest and occupation of California, and it produced a kind of killing that Madley appropriately calls “pedagogic,” which would persist long afterward. Its rationale was a 19th-century version of shock and awe: At the slightest hint of a threat, Americans would inflict indiscriminate violence. Indians did not have to attack; Americans had only to feel threatened. In a mirror image of the way some Germans, Hungarians, and Americans feel threatened by the presence of Muslim asylum seekers in their countries today, Americans felt threatened by Indians. John C. Frémont began the bloodshed in 1846 by killing Wintus in Northern California because Americans feared the Wintus would attack them. The Americans were armed with Hawken rifles that could kill from 200 yards; the Wintus had bows. The result, as Americans described it, was the “slaughter” of 120 to 175 Indians. Frémont intended this as exemplary violence meant to terrify Indians and inoculate whites against attack.

The justification of exemplary violence was (and still is) that it eliminates the need for further violence. In California, the justification was empty: All that Americans really offered Indians were different ways to die. As gold miners wrecked the salmon streams and drove off game, as cattle and swine fed on the grasses and acorn crops that formed the basis of Native subsistence, exemplary violence forced Indians to choose between slaughter and starvation. When desperate Indians killed cattle and swine, they opened themselves up to disproportionate retaliatory violence. Americans held Indians collectively responsible for any injury suffered by whites. And they were relentless: When Indians tried to prevent Americans’ entry into their territory, they were attacked. Indians who took up gold mining and tried to defend their lands were slaughtered. When Indians retaliated against white violence, Oregonians (among the first of the forty-niners) shot them on sight, hunting them like animals and instituting a practice that would last for years.

Americans also deployed violence to secure forced labor. Inside and outside the gold-mining region, miners and ranchers sought to imitate and improve on Mexican labor practices by forcing Indians to work for them. The California constitutional convention denied Indians citizenship and condoned what amounted to permanent indenture. California’s Orwellian Act for the Government and Protection of Indians anticipated the Southern black codes that followed the Civil War. Having stripped them of their legal rights and provided for their arrest as vagrants, officials could auction off Indian “convicts” to pay their fines. Indian children could be taken from their parents and indentured until age 15 for females, 18 for males.

The law also formalized existing practices. Among the more horrible stories told by Madley is the one involving Charles Stone and Andrew Kelsey. They raised large amounts of livestock on lands they had appropriated from the Eastern Pomo and Clear Lake Wappo, whom they’d reduced to servile labor under threat of violence. They confiscated the Indians’ weapons, allowed them only meager rations, prohibited them from hunting, and punished them viciously when they killed cattle. Sexual violence against Indian women became routine; those who resisted were tortured. Against this and more, the Indians rebelled, killing Stone and Kelsey in 1849.

The slayings brought the US Dragoons down upon them. The soldiers killed any Indians they found, regardless of their involvement in the deaths. Vigilantes followed in the soldiers’ wake, driving the Indians off their lands in Napa, Sonoma, and around Santa Rosa. Many of the refugees were soon starving. The killings reached their peak when detachments from the US Dragoons and Artillery attacked Pomos on Bloody Island in Clear Lake. They shot the men and bayoneted and clubbed the women and children. As usual in such massacres, there was no careful counting of the dead; between 200 and 400 people were killed. The army followed this up with an attack on a village on the Russian River. The soldiers killed everyone they could find, from 75 to 100 people. (Two soldiers were wounded.) More killings followed. And so it would go, spreading across a very large state for nearly 25 straight years.

California’s laws, having created a system that encouraged slaving raids and the kidnapping of children, allowed slavers to act with impunity. Indians couldn’t testify against whites, and even when whites were willing to testify, the courts wouldn’t convict. Slaving existed throughout the period, but the practice reached its peak, ironically, when the Republicans—who rose to national power on the basis of their objections to black slavery—won the election in California under Leland Stanford during the Civil War.

The participation of federal troops and state militia in the violence, and the passage of laws that allowed Indian enslavement to flourish, emphasized the active participation of both the state and federal governments in the genocide. There is some truth in the older narrative about federal attempts to protect the Indians, but those efforts were feeble and ineffective. The Senate rejected the original treaties negotiated in California because of opposition from Californians who wanted nothing valuable reserved for Indians. The federal government did establish reservations at Round Valley and elsewhere, but it refused to protect the Indians who were removed there or to provide them with adequate supplies and rations. J. Ross Browne, a federal official sent to Round Valley to investigate conditions, reported that in the winter of 1858–59, whites slaughtered “a hundred and fifty peaceable Indians,” including nursing mothers and small children. Slavers and white squatters invaded the reservations. Indians often fled, preferring the dangers of starvation and attack outside the reservations to the hunger, disease, and assaults they suffered within them. It was no wonder they came to look on Round Valley “rather as a hell than as a home.”

It was not just the federal sins of omission that matter here; the funding that the US government provided for California’s militia expeditions made attacking Indians possible and profitable. When the government expended funds to pay for past assaults on Indians, it encouraged new ones. Fighting Indians became a source of profit; men enlisted for the pay, and the government provided it. During the Civil War, the federal government recruited the California Volunteers, who existed largely to fight Indians. The Volunteers continued their carnage over much of California and expanded it into the state’s deserts to the southeast. Congress proved far more generous appropriating money for killing Indians than for feeding them—and even when it knew that Indians on the reservations were starving, Congress cut the funding for their rations.

By the time of the Civil War, the killing had become the backdrop for California politics, and condoning it the price of public office. Nearly 20 years into the slaughter, Stanford rationalized the calling out of troops and a bill to supplement the pay of the California Volunteers as self-defense. He demanded “absolute protection to our citizens from these repeated incursions of hostile Indians.” The result? Still more indiscriminate killing of Indians.

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How many Indians died from this lethal combination of violence, enslavement, hunger, and disease is difficult to determine. Those inclined to challenge Madley’s account will cite the numbers, either minimizing the deaths or attributing them to other causes. Madley relies on two different figures to assess the toll. The first is the sharp decline in the Indian population. Working from the standard estimates of Sherburne Cook, a prominent 20th-century anthropologist, Madley estimates that between 1846 and 1873, the number of California Indians—already halved during the Spanish and Mexican periods—plunged by another 80 percent, reaching a nadir of about 30,000 people. Roughly 65,000 people died in the 1850s alone. Madley attributes this tremendous death toll to both the violence and its aftermath. The second figure—and the focus of the book—calculates the number of Indians who died violently at American hands between 1846 and 1873. Madley estimates that somewhere between 9,000 and 16,000 Indians were killed by Americans during this period.

At the end of his book, Madley briefly touches on two well-known stories, one about Ishi and the other about Kintpuash, or “Captain Jack.” Ishi became famous as the last “wild” Indian in California, the only surviving member of a subtribe of the Yana who—desperate and hungry—finally came out of the mountains in the early 20th century. Kintpuash was the Modoc war leader who held off American soldiers and militia in an epic siege near what is today the Lava Beds National Monument. Both stories are usually told as set pieces, isolated from or only tangentially connected to the larger history of California.

In 1961, Theodora Kroeber published Ishi in Two Worlds, an affecting story of the friendship and collaboration between Ishi and a group of Berkeley anthropologists associated with her husband, Alfred Kroeber. Theodora Kroeber never conceals the slaughter of the Yana Indians; she tells the same story that Madley does of the 1871 massacre of 30 Yana, including children, for killing a steer.

For Madley, the massacre is an end point, the last large-scale killing of California Indians, and simply another atrocity in a quarter-century of atrocities. Kroeber, on the other hand, offered the story as a kind of beginning, the introduction to a tale of reconciliation and redemption. Because she focused only on the history of the Yana, she could use Ishi as a stock figure in American mythology—the last of his tribe, who offers forgiveness. She turned Ishi’s friendship and partnership with her husband into at least a literary reconciliation, providing closure to a horrible history and the promise of a more benign future. Madley offers neither reconciliation nor redemption. How could he do otherwise, when the slaughter of the Yana was merely a kind of coda to the genocide of which it is a part? (The Americans killed virtually every member of Ishi’s community.)

Like Ishi’s tale, the story of Kintpuash is usually detached from the slaughter of California Indians as a whole. On the surface, the Modoc War and Captain Jack’s skillful and courageous defense of his people seem different from the stories that Madley tells. The Modoc War, for all its injustice, pitted soldiers and militia against well-armed warriors who were able to defend themselves. No matter how one-sided, this was a war. Madley, however, connects Captain Jack and the Modocs to his larger story of genocide, because the war marked the end of American attacks on the Modocs. Genocide explains why Captain Jack orchestrated the actual and attempted murder of American negotiators: Twenty years earlier, the Americans had lured the Modocs to a supposed peace conference and slaughtered them. Among the victims of the Lost River Massacre was Captain Jack’s father. The Americans vowed to exterminate the Modocs, and they did execute Kintpuash and others, but there was no campaign of extermination. An era had ended. This was closure of sorts, but it was an ending without redemption.

Theodora Kroeber’s efforts to reveal and heal were doubtless well-intentioned, but they were only partly successful—and, needless to say, they’ve worked better among whites than Indians. Kroeber’s book is still taught in California public schools, and the lesson can seem to be that the tragedy is now behind us; all is forgiven. But far more groups than the Yana were affected by the American attacks, and today some California Indians complain that although the schools teach their children about other genocides—in Europe, Armenia, and Rwanda—the slaughter of their own people remains shrouded in silence.

For this reason, Madley is right to downplay Ishi: What happened to the Yana wasn’t unique, and the remarkable story of one remarkable man cannot heal these wounds or mask the larger horror in which prominent historical figures took part. At Stanford University, where I teach, this year is the 125th anniversary of its founding. Stanford has predictably made it a fund-raising moment. Among the commemorative events are some entitled “Celebrating the Founders”: Leland Stanford, who as California governor called out the militia against the Indians, and his wife Jane. These commemorations are taking place even as the university has formed a committee to “establish principles for reconsidering and renaming campus streets and buildings” whose current names are offensive to many. This reevaluation of names and symbols is something of a commonplace on campuses these days, and it’s often derided. At Stanford, there’s a particularly interesting twist: The committee is to apply those “principles ‘first and foremost’ to places that honor Junípero Serra, whose mixed legacy as the founder of the mission network in California has raised concerns among students.” In light of Benjamin Madley’s An American Genocide, the juxtaposition of reconsidering Junípero Serra while glorifying Leland Stanford makes for an odd California moment, even by Palo Alto standards. To quote Secretary of State John Kerry again, naming genocidal crimes is important—but as California Indians already know, some are easier to name than others.

Editor’s note: An earlier version of this article stated that Modoc war leader Kintpuash held off American soldiers and militia in a siege at Mount Lassen. The siege was near what is today the Lava Beds National Monument. The text has been updated.