Disunion follows the Civil War as it unfolded.

On Dec. 21, 1866, a year and a half after Gen. Robert E. Lee and Gen. Ulysses S. Grant ostensibly closed the book on the Civil War’s final chapter at Appomattox Court House, another soldier, Capt. William Fetterman, led cavalrymen from Fort Phil Kearny, a federal outpost in Wyoming, toward the base of the Big Horn range. The men planned to attack Indians who had reportedly been menacing local settlers. Instead, a group of Arapahos, Cheyennes and Lakotas, including a warrior named Crazy Horse, killed Fetterman and 80 of his men. It was the Army’s worst defeat on the Plains to date. The Civil War was over, but the Indian wars were just beginning.

These two conflicts, long segregated in history and memory, were in fact intertwined. They both grew out of the process of establishing an American empire in the West. In 1860, competing visions of expansion transformed the presidential election into a referendum. Members of the Republican Party hearkened back to Jefferson’s dream of an “empire for liberty.” The United States, they said, should move west, leaving slavery behind. This free soil platform stood opposite the splintered Democrats’ insistence that slavery, unfettered by federal regulations, should be allowed to root itself in new soil. After Abraham Lincoln’s narrow victory, Southern states seceded, taking their congressional delegations with them.

Never ones to let a serious crisis go to waste, leading Republicans seized the ensuing constitutional crisis as an opportunity to remake the nation’s political economy and geography. In the summer of 1862, as Lincoln mulled over the Emancipation Proclamation’s details, officials in his administration created the Department of Agriculture, while Congress passed the Morrill Land Grant Act, the Pacific Railroad Act and the Homestead Act. As a result, federal authorities could offer citizens a deal: Enlist to fight for Lincoln and liberty, and receive, as fair recompense for their patriotic sacrifices, higher education and Western land connected by rail to markets. It seemed possible that liberty and empire might advance in lock step.

But later that summer, Lincoln dispatched Gen. John Pope, who was defeated by Lee at the Second Battle of Bull Run, to smash an uprising among the Dakota Sioux in Minnesota. The result was the largest mass execution in the nation’s history: 38 Dakotas were hanged the day after Christmas 1862. A year later, Kit Carson, who had found glory at the Battle of Valverde, prosecuted a scorched-earth campaign against the Navajos, culminating in 1864 with the Long Walk, in which Navajos endured a 300-mile forced march from Arizona to a reservation in New Mexico.

That same year, Col. John Chivington, who turned back Confederates in the Southwest at the Battle of Glorieta Pass, attacked a peaceful camp of Cheyennes and Arapahos at Sand Creek in Colorado. Chivington’s troops slaughtered more than 150 Indians. A vast majority were women, children or the elderly. Through the streets of Denver, the soldiers paraded their grim trophies from the killing field: scalps and genitalia.

In the years after the Civil War, federal officials contemplated the problem of demilitarization. Over one million Union soldiers had to be mustered out or redeployed. Thousands of troops remained in the South to support Reconstruction. Thousands more were sent West. Set against that backdrop, the project of continental expansion fostered sectional reconciliation. Northerners and Southerners agreed on little at the time except that the Army should pacify Western tribes. Even as they fought over the proper role for the federal government, the rights of the states, and the prerogatives of citizenship, many Americans found rare common ground on the subject of Manifest Destiny.

Related Disunion Highlights Explore multimedia from the series and navigate through past posts, as well as photos and articles from the Times archive. See the Highlights »

During the era of Reconstruction, many American soldiers, whether they had fought for the Union or the Confederacy, redeployed to the frontier. They became shock troops of empire. The federal project of demilitarization, paradoxically, accelerated the conquest and colonization of the West.

The Fetterman Fight exploded out of this context. In the wake of the Sand Creek Massacre, Cheyennes, Arapahos and various Sioux peoples forged an alliance, hoping to stem the tide of settlers surging across the Plains. Officials in Washington sensed a threat to their imperial ambitions. They sent Maj. Gen. Grenville Dodge, who had commanded a corps during William Tecumseh Sherman’s pivotal Atlanta campaign, to win what soon became known as Red Cloud’s War. After another year of gruesome and ineffectual fighting, federal and tribal negotiators signed the Treaty of Fort Laramie, guaranteeing the Lakotas the Black Hills “in perpetuity” and pledging that settlers would stay out of the Powder River Country.

The Indian wars of the Reconstruction era devastated not just Native American nations but also the United States. When the Civil War ended, many Northerners embraced their government, which had, after all, proved its worth by preserving the Union and helping to free the slaves. For a moment, it seemed that the federal government could accomplish great things. But in the West, Native Americans would not simply vanish, fated by racial destiny to drown in the flood tide of civilization.

Red Cloud’s War, then, undermined a utopian moment and blurred the Republican Party’s vision for expansion, but at least the Grant administration had a plan. After he took office in 1869, President Grant promised that he would pursue a “peace policy” to put an end to violence in the West, opening the region to settlers. By feeding rather than fighting Indians, federal authorities would avoid further bloodshed with the nation’s indigenous peoples. The process of civilizing and acculturating Native nations into the United States could begin.

This plan soon unraveled. In 1872, Captain Jack, a Modoc headman, led approximately 150 of his people into the lava beds south of Tule Lake, near the Oregon-California border. The Modocs were irate because federal officials refused to protect them from local settlers and neighboring tribes. Panic gripped the region. General Sherman, by then elevated to command of the entire Army, responded by sending Maj. Gen. Edward Canby to pacify the Modocs. A decade earlier, Canby had devised the original plan for the Navajos’ Long Walk, and then later had helped to quell the New York City Draft Riots. Sherman was confident that his subordinate could handle the task at hand: negotiating a settlement with a ragtag band of frontier savages.

But on April 11, 1873, Good Friday, after months of bloody skirmishes and failed negotiations, the Modoc War, which to that point had been a local problem, became a national tragedy. When Captain Jack and his men killed Canby – the only general to die during the Indian wars – and another peace commissioner, the violence shocked observers around the United States and the world. Sherman and Grant called for the Modoc’s “utter extermination.” The fighting ended only when soldiers captured, tried, and executed Captain Jack and several of his followers later that year. Soon after, the Army loaded the surviving Modocs onto cattle cars and shipped them off to a reservation in Indian Territory (present-day Oklahoma).

President Grant’s Peace Policy perished in the Modoc War. The horror of that conflict, and the Indian wars more broadly, coupled with an endless array of political scandals and violence in the states of the former Confederacy – including the brutal murder, on Easter Sunday 1873 in Colfax, La., of at least 60 African-Americans – diminished support for the Grant administration’s initiatives in the South and the West.

The following year, Lt. Col. George Armstrong Custer claimed that an expedition he led had discovered gold in the Black Hills – territory supposedly safeguarded for the Lakotas by the Fort Laramie Treaty. News of potential riches spread around the country. Another torrent of settlers rushed westward. Hoping to preserve land sacred to their people, tribal leaders, including Red Cloud, met with Grant. He offered them a new reservation. “If it is such a good country,” one of the chiefs replied, “you ought to send the white men now in our country there and leave us alone.” Crazy Horse, Sitting Bull and other warriors began attacking settlers. Troops marched toward what would be called the Great Sioux War.

Photo

Early in 1876, Lt. Gen. Philip Sheridan, the Army’s commander on the Plains, insisted that all Indians in the region must return to their reservations. The Lakotas and Northern Cheyennes refused. That summer, as the nation celebrated its centennial, the allied tribes won two victories in Montana: first at the Rosebud and then at the Little Bighorn. The Army sent reinforcements. Congress abrogated the Lakotas’ claims to land outside their reservation. The bloodshed continued until the spring of 1877, when the tribal coalition crumbled. Sitting Bull fled to Canada. Crazy Horse surrendered and died in federal custody.

The final act of this drama opened in 1876. When federal officials tried to remove the Nez Perce from the Pacific Northwest to Idaho, hundreds of Indians began following a leader named Chief Joseph, who vowed to fight efforts to dispossess his people. Sherman sent Maj. Gen. Oliver Otis Howard, formerly head of the Freedmen’s Bureau, to quiet the brewing insurgency. As Howard traveled west, the 1876 election remained undecided. The Democrat Samuel Tilden had outpolled the Republican Rutherford B. Hayes by nearly 300,000 votes. But both men had fallen short in the Electoral College. Congress appointed a commission to adjudicate the result. In the end, that body awarded the Oval Office to Hayes. Apparently making good on a deal struck with leading Democrats, Hayes then withdrew federal troops from the South, scuttling Reconstruction.

Less than two months after Hayes’s inauguration, Howard warned the Nez Perce that they had 30 days to return to their reservation. Instead of complying, the Indians fled, eventually covering more than 1,100 miles of the Northwest’s forbidding terrain. Later that summer, Col. Nelson Miles, a decorated veteran of Antietam, the Peninsula Campaign and the Appomattox Campaign, arrived to reinforce Howard. Trapped, Chief Joseph surrendered on Oct. 5, 1877. He reportedly said: “I am tired. My heart is sick and sad. From where the sun now stands, I will fight no more forever.”

One hundred and fifty years after the Civil War, collective memory casts that conflict as a war of liberation, entirely distinct from the Indian wars. President Lincoln died, schoolchildren throughout the United States learn, so that the nation might live again, resurrected and redeemed for having freed the South’s slaves. And though Reconstruction is typically recalled in the popular imagination as both more convoluted and contested – whether thwarted by intransigent Southerners, doomed to fail by incompetent and overweening federal officials, or perhaps some combination of the two – it was well intended nevertheless, an effort to make good on the nation’s commitment to freedom and equality.

But this is only part of the story. The Civil War emerged out of struggles between the North and South over how best to settle the West – struggles, in short, over who would shape an emerging American empire. Reconstruction in the West then devolved into a series of conflicts with Native Americans. And so, while the Civil War and its aftermath boasted moments of redemption and days of jubilee, the era also featured episodes of subjugation and dispossession, patterns that would repeat themselves in the coming years. When Chief Joseph surrendered, the United States secured its empire in the West. The Indian wars were over, but an era of American imperialism was just beginning.

Follow Disunion at twitter.com/NYTcivilwar or join us on Facebook.

Photo

Photo

Boyd Cothran is an assistant professor of United States Indigenous and cultural history at York University in Toronto and the author of “Remembering the Modoc War: Redemptive Violence and the Making of American Innocence.” Ari Kelman is the McCabe-Greer Professor of the Civil War Era at Penn State and the author of “A Misplaced Massacre: Struggling Over the Memory of Sand Creek,” which won the Bancroft Prize in 2014, and, with Jonathan Fetter-Vorm, “Battle Lines: A Graphic History of the Civil War.” Cothran and Kelman are both writing books about the relationship between Reconstruction and Native American history.

Follow The New York Times Opinion section on Facebook and Twitter, and sign up for the Opinion Today newsletter.

