Praise came fast, and then the backlash, especially against the claim that the nation’s true founding should be dated not to the 1776 American Revolution but to 1619, when the first group of 20 to 30 enslaved Africans arrived in North America and were sold to Jamestown settlers. The editors and authors of 1619 are working in the cockpit of Trumpism, with racism and inequality renascent, so their dark take on US history is understandable. But here’s Martin Luther King Jr. in 1963 writing near the top of the mountain. Liberalism was seemingly triumphant, on the cusp of passing historic civil rights legislation. If ever there was a moment to put forward an optimistic view of US history—of a country about to fulfill its “promissory note” of equality—this was it. Still, King feels compelled to point out the “broader dimensions of the evil” of US history, of its “myth” of equality:

Our nation was born in genocide, when it embraced the doctrine that the original American, the Indian, was an inferior race. Even before there were large numbers of Negroes on our shore, the scar of racial hatred had already disfigured colonial society. From the sixteenth century forward, blood flowed in battles over racial supremacy. We are perhaps the only nation which tried as a matter of national policy to wipe out its indigenous population.

Expectedly, much of the criticism of The 1619 Project comes from political conservatives. But a group of liberal historians reacted harshly as well, among them Princeton’s Sean Wilentz, who, along with four other esteemed scholars—James McPherson, Gordon Wood, Victoria Bynum, and James Oakes—sent a letter to the Times demanding a retraction of the claim, made by Hannah-Jones, that “one of the primary” causes of the American Revolution was that colonists “wanted to protect the institution of slavery.” Wood, Oakes, McPherson, and Bynum also gave extended, critical interviews about the project covering a wide range of topics: colonial history, the Civil War, Abraham Lincoln’s views on race, Thomas Jefferson’s late-in-life turn toward pro-Southern extremism, the relationship of ideas to politics and economics, and the links between capitalism and slavery. Wood and Oakes, especially, objected to Hannah-Jones’s argument that the American Revolution was fought to defend slavery, and Wilentz, in a comment to The Atlantic, took exception to her remark that African Americans fought for their rights “largely alone.”

Striking is what was not discussed, and that’s what King noted in 1963: indigenous subjugation. The historians mentioned above said not a word, either in their collective letter or in their extensive interviews, about the dispossession of native peoples, the destruction of their societies, and their deportation west.

The omission is odd. For whether their criticism was motivated by a desire to defend a Whiggish narrative of liberal progress (Wilentz’s position) or insist on a stronger focus on political economy (Oakes’s concern), indigenous subjugation is key to understanding the history here being debated. Imperial expansion west over stolen Indian land shaped the American Revolution’s relationship to slavery. Expansion west drove the dynamism of the United States economy. And expansion west ignited slavery’s vast and rapid postrevolutionary growth, and allowed for its endurance, long past its abolition in every other country in the Americas (save for Brazil and Cuba), accounting for its deep and lasting imprint on US political culture, economics, and institutions.

American revolutionaries might have argued over slavery, and what place unfree labor would have in a republic founded on the ideal of liberty. But there was one thing that nearly all agreed on: the right to move west. British Americans, before their break with London, chafed at what was called the “Proclamation Line.” Running along the crest of the Alleghenies, the demarcation was made by the British Crown after its 1763 victory in the Seven Years’ War against France, as an effort to sequester white settlers on the Atlantic Coast. With British subjects already moving through the mountain passes, the policy became a major source of resentment against colonial rule. Settlers—the “overflowing Scum of the Empire,” as a British governor described the drifters and squatters who rushed down the Mississippi Valley—wanted land, which brought them into deadly conflict with Native Americans. In 1763, for instance, the Scotch-Irish Paxton Boys rampaged through Pennsylvania, murdering over a dozen Conestoga, scalping their victims, mutilating their corpses, and breaking up their communities (Dwight D. Eisenhower’s great-great-great grandfather, Hans Eisenhauer, was a Pennsylvania Indian killer during this time).

Not just material interests drove settlers west. The United States was founded on the idea that the ability to move wasn’t just a natural right but a condition of all other natural rights, a guarantor of many different kinds of virtue. Franklin provided an early political economy: Unlike in Europe, “labour will never be cheap” as long as farmers can continue moving west. James Madison offered a political theory: “Extend the sphere,” he said, and you’ll dilute factionalism and mitigate economic conflict. And Jefferson, two years before his draft of the Declaration of Indepedence, presented a moral history: Our “Saxon ancestors,” Jefferson wrote, “left their native wilds and woods in the North of Europe” and “possessed themselves of the Island of Britain.” As they did so, no German prince presumed to claim “superiority” over them. By what law, then, did the Crown presume to stop colonists from settling “the wilds of America”?

The American Revolution answered: none at all. The new nation came into the world doubling its size. The treaty recognizing the independence of the original 13 colonies ceded to them the territory between the Alleghenies and the Mississippi. The United States then proceeded to move swiftly—as if weightless, as the Mexican diplomat and writer Octavio Paz put it—across the West.

What would have happened if the United States had stayed confined, either east of the Alleghenies or of the Mississippi? What if the new nation hadn’t used its full federal apparatus to cleanse its eastern lands of Native Americans? Counterfactuals are a mug’s game, which historians anyway like to play (even if many consider them an invalid form of historical reasoning). Economists, though, have no problem with asking “What if?” The Berkeley economist Bradford DeLong isolated some variables and built a model that suggested that a “little America…penned behind the Appalachians would probably have seen its living standards and productivity levels not growing at 1% per year from 1760 to 1860 but shrinking.” Wages, as a result, would have been lower than they actually were, which would have decreased European migration somewhat but not much, considering the direness of rural life in Europe.

The history of chattel slavery would have been different in “little America.” With large numbers of immigrants working for lower wages, in a more constricted economy, fights over the moral meaning of labor, free and slave, which the historians who criticize The 1619 Project make much of, might have come to a head earlier. Or maybe not. For without taken indigenous land to expand into (land that was used as collateral for loans to finance buying more slaves and building more plantation, which in turn contributed to the growth of the cotton, real estate, finance, and insurance industries), slavery probably wouldn’t have transformed into the even larger monstrosity that it did become. Many Northerners and Southerners, Gordon Wood says, sounding wistful, as if he wishes he were living in little America, “thought slavery was on its last legs and that it would naturally die away.” And maybe the racism forged in a rump slavery would itself be a rump, and wouldn’t have had the lasting impact that it did.

But “big America” is what we got, thanks to a “national policy to wipe out its indigenous population,” as King noted in 1963. The United States flew over the continent like a whirligig, with not one “removal” but hundreds of removals, not one Trail of Tears, but many, with massacre after massacre, until Native Americans were reduced. This expansion—the acquisition of Florida, the Louisiana Purchase, Jackson’s Indian removal, the incorporation into the union of Texas, founded as a slaver’s utopia, and Oregon, founded as a white supremacist arcadia, and the taking of a third of Mexico—delayed a political reckoning with slavery, even as it provided the conditions for the robust progression of slavery. By the 1850s, chattel slavery had, in big America, insinuated itself into national life, into politics, law, philosophy, medicine, the new science of mental health, culture, city planning, and of course economics, in ways that, as The 1619 Project argues, last till today. It was during the Jacksonian period of imperial expansion, Indian removal, and the fast growth of slavery that a minimalist interpretation of the Constitution’s regulatory and fiscal power, and a maximalist interpretation of its war power, took shape—an interpretation that to a large degree remains regnant.

Indian removal opened the floodgates, allowing, as one legal theorist would describe the Age of Jackson, “an irresistible tide of Caucasian democracy” to wash over the land. King Cotton extended its dominion through the South, creating great wealth, along with greater forms of racial domination over both enslaved and free blacks. At the same time, Native Americans were driven west, and the white settlers and planters who got their land experienced something equally unprecedented: an extraordinary degree of power and popular sovereignty. Never before in history could so many white men consider themselves so free. Jacksonian settlers moved across the frontier, continuing to win a greater liberty by putting down people of color, and then continuing to define their liberty in opposition to the people of color they put down.

The 1846 war on Mexico deepened the associations of white skin with supremacy, dark skin with subjugation, and expansion with freedom. The nation’s elites “placed their most restless and desperate citizens upon the throat of Mexico,” as the historian Paul Foos described the looting, civilian murder, and terror that US troops—comprised of state militia volunteers and Army regulars—inflicted on Mexicans. Mexico put up more of a fight than the US politicians who plumped for the war said it would. As fighting dragged on for nearly two years, US soldiers committed crimes on Mexicans so terrible that, as General Winfield Scott, commander of US forces, said, they made “heaven weep.” The war was fought in an extremely decentralized manner, with officers’ barely exercising control over their troops, who experienced the violence they committed on Mexicans and Native Americans—“the repetition of the most heinous offenses, murder, rapine, robbery, and rape,” as one US newspaper described them—as a form of liberty.

The United States won the war, and many veterans returned east, to New England’s manufacturing towns or to New York’s Bowery, their battle-hardened racism working its way into local politics and into organizations that were potentially egalitarian, such as labor associations, and the Free Soil movement. Others went west, into California and up into Oregon. Armed with federally supplied rifles, an ample stock of bullets, and the promise of bounty land, they understood Western settlement to be a sequel to the war they had just won, and the genocide that took place on the Pacific Coast its last, long battle. “A war of extermination,” the first US Anglo governor of California predicted in 1851, “will continue to be waged between the races, until the Indian race becomes extinguished.”

Others spread out into the Midwest, into Kansas and Missouri, carrying their blood-soaked entitlement with them. War with Mexico simultaneously delayed and worsened the sectional crisis. In this sense, then, imperial expansionism served as both valve and throttle, with each conflict simultaneously venting the hatreds produced by the last while creating the conditions for the next.

The scholars who criticized The 1619 Project rightly argue that the moral debates, economic conflicts, and complicated politics of the Civil War shouldn’t be easily dismissed. There’s heroism, exercised by people of all colors, to be appreciated, which today might help us climb out of our current abyss. But it’s also important to recognize the way in which imperial expansion, including the ongoing dispossession of Native Americans, allowed the United States to continue its great evasion, its ability to take social conflicts that seemed irresolvable in the here and now and imagine their resolution in the there and then: there beyond the line of settlement, and then when the United States wins the West or opens the China market.

It wasn’t just the localized power of Southern elites that ended radical Reconstruction, the closest this nation came to having an honest reckoning with the consequences of slavery. In the struggle between North and South over the direction of a postbellum nation, access to Western lands played a decisive part. As the historians Boyd Cothran and Ari Kelman write, Northerners and Southerners in the years after the Civil War found “rare common ground” on the need to acquire more ground. They agreed on nearly nothing, only that the “Army should pacify Western tribes.” White Southerners bitterly opposed Reconstruction, and especially the hated Freedmen’s Bureau, but they came together with Northerners “on the subject of Manifest Destiny.”

The overseas frontier—wars and military occupations in Cuba, the Dominican Republic, the Philippines, Nicaragua, and Haiti—acted as a prism, blurring together the color line that existed at home and abroad. Southerners, in each military occupation and prolonged counterinsurgency they fought, could replay the dissonance of the Confederacy again and again. They could fight in the name of the loftiest ideals—liberty, valor, self-sacrifice, camaraderie—while putting down people of color. The body count in the Caribbean and Pacific was high. Hundreds of thousands died through the 1930s, either directly at the hands of US soldiers or from disease, famine, and exposure. Letters from soldiers, first in the 1898 campaign and then later in Nicaragua, Haiti, and the Dominican Republic, are notably similar, lightheartedly narrating to family and friends how they would shoot “niggers,” take “nigger scalps,” lynch “niggers,” release “niggers” into the swamp to die, water-torture “niggers,” and use “niggers for target practice.”

As Southerners steadily took the lead in the US military campaigns outward, all the dread, resentment, and hate generated by that campaign “poured back within the frame of the South itself,” as the Southern writer W. J. Cash wrote in his 1941 classic, The Mind of the South, and blended together. Over there, foreign enemies could be called niggers, and over here, domestic enemies—labor, farmer, and civil rights organizers, both people of color and their white allies—could be called subversives and anti-American: Many of the white vigilantes who led the terror campaign against black communities, in places like Wilmington, North Carolina, in 1898; Elaine, Arkansas, in 1919 (where veterans, with help from the US Army, slaughtered 237 sharecroppers for trying to organize a union); or the 1921 Tulsa massacre, were veterans.

Rather than atonement and reckoning, the United States offered war and conquest as a way to forge national unity. In fact, war became America’s ideal form of atonement, a way to deal with the past by fleeing forward into the future, by recycling the traumas caused by the last war into new wars.

We are going to need a bigger project, of the kind that Martin Luther King Jr. laid out in 1963. By focusing on the horrors inflicted on Native Americans, by arguing for the unprecedented nature of removal, King was doing more than adding yet another oppressed group to history’s pantheon of victims. Rather, he was reaching for a holistic understanding of how racism is historically reproduced down the generations.

“We elevated” the war against Native Americans “into a noble crusade,” King said, founding our national identity on Indian killing. Imperial expansion became a way of life, one that reinforced deep-seated pathologies and provided mythic justification for a volatile, racialized individualism. Imperial expansion led to alienation, social isolation, free-floating aggression, and fantasies that life was an endless game of cowboys and Indians, played out in all the nation’s endless wars. King, who by this time considered himself a socialist, hoped to build a movement that would achieve the “mass application of equality to jobs, housing, education, and social mobility.” He was acutely aware of the structural barriers to that goal. But he was also attuned to the psychic barriers that blocked full social equality.

Hannah-Jones writes that African Americans mostly “fought back alone.” King said much the same thing when he described nonviolent civil rights activists who faced jeering mobs with an “agonizing loneliness.” King here wasn’t talking about a lack of white allies, or individual isolation. He was talking about the loneliness that comes from fighting for social justice in a nation that is deeply, militantly, antisocial. “There is,” he said, “an individualism that destroys the individual,” that denies the interdependency of existence.

Starting around the early 1960s, King began to use the idea of the social frontier to put forward a counter value structure, an alternative to an ideal of freedom forged in centuries of subjugating people of color. African Americans, he said, confronted a reality “as harsh and demanding as that of the pioneer on the untamed frontier.” That harshness forged character and weeded out frivolity; it sharpened “knowledge and discipline…courage and self- sacrifice.” For King, then, nonviolent resistance was more than a tactic. The ability to fight on the “social frontier,” to forge a path through the “wilderness of segregation” without losing oneself to justifiable anger, without giving in to rage or the despair of loneliness, he said, contained the embryo of an alternative society, a way to free the nation from its past, to overcome its cultish adherence to frontier violence and create a beloved, social community.

Then came Vietnam, and King confronted his own agonizing loneliness. First for staying guiltily silent, not wanting to break his productive, for a time, alliance with the Democratic Party. And then, after he spoke out, when he was abandoned by people he thought were his allies and friends.

King started to publicly criticize the war in 1966. His cri de coeur came on April 4, 1967, when he gave his “Beyond Vietnam” speech in Riverside Church in Manhattan, to an overflow crowd of thousands. There, King didn’t just condemn the US war in Southeast Asia. He condemned all of it: the country’s long history of expansion, its “giant triplets of racism, materialism, and militarism,” and a political culture where “profit motives and property rights are considered more important than people.”

King wasn’t just breaking with the Cold War liberal consensus, which conditioned support for civil rights at home on backing anti-communism abroad. Rather, his protest entailed the refutation of an older, more primal premise. The nation was founded on the idea that expansion was necessary to achieve and protect social progress. Over the centuries, that idea was realized, again and again, through war. Extending the vote to the white working class went in hand with Indian removal; the military defeat of the Confederacy by the Union Army didn’t just end slavery but also marked the beginning of the final pacification of the West, with the conquered frontier continuing as an important basis of Caucasian democracy. Millions of acres were distributed to veterans. By the time African Americans started entering the armed forces in significant numbers, with the war of 1898, there was no more frontier land to hand out. But military service remained one of the country’s most effective mechanisms of social mobility, for African Americans as well as for working-class people in general, with the G.I. Bill of Rights providing education, medical care, and homeownership to veterans. King’s dissent, therefore, signaled a schism in US politics worthy of his namesake.

To “go beyond Vietnam” didn’t just mean splitting from the New Deal coalition by demanding an exit from Southeast Asia. It meant breaking with the devil’s bargain that social progress could be achieved in exchange for support for imperial expansion. King well understood that while war made some progress possible, it also threatened progress, activating the backlashers, revanchists, and racists who run through US history. For all that war turns reform into a transactional arrangement (some suffragists, for instance, traded their support for Woodrow Wilson’s war in exchange for his support for their right to vote, as did some trade unionists for his support for labor rights), and for all that imperial expansion worked as a safety valve (helping to vent extremism outward), it also created the aggressive, security- and order-obsessed political culture that King gave his life fighting against.

King was punished for his dissent. Many of his allies, black and white, abandoned him. Others attacked him. The Washington Post essentially gave King notice that his services would no longer be needed. “He has diminished his usefulness,” its editors said. Meanwhile, the FBI stepped up its campaign of surveillance and harassment against King and his family. This campaign had been running since at least 1962, and not one of King’s white allies of considerable influence—not John Kennedy, not Robert Kennedy, not Lyndon Johnson—ever ordered the bureau to stand down. That’s what it means to “fight alone.”

A prophet outcast, King continued, during the last year of his life, to speak out against the war. He put forth, in a series of sermons and press conferences, a damning analysis. Imperial expansion abroad, he argued, quickened domestic polarization. The “flame throwers in Vietnam fan the flames in our cities,” he said; “the bombs in Vietnam explode at home.” Racists killing brown people abroad became more racist. Opponents of war at home became more militant. Imperial expansion had long served to vent domestic extremism outward. But at some point, the vent would stop working. “There is such a thing as being too late,” King said in his Riverside Church speech, warning that the United States, even if it did try to reverse course, might not be able to steer away from self-destruction. “Over the bleached bones and jumbled residues of numerous civilizations are written the pathetic words, ‘Too late.’” King was executed a year to the day after that speech.