Some time ago, while working on my book Mustang: The Saga of the Wild Horse in the American West, I learned about a strange and heartbreaking moment that had transpired outside Sitting Bull’s cabin while he was being assassinated during an attempted arrest. A horse was tethered to a railing, and at the sound of gunfire he started to “dance,” trained to do such a thing while he was in the Wild West, Buffalo Bill’s famous spectacle of which Sitting Bull was a part for four months during 1885. I couldn’t shake the image and as I began to look into it, I learned that the horse was a gift to Sitting Bull from Buffalo Bill, presented to Sitting Bull when he left the show to go home. The fact that Buffalo Bill had given Sitting Bull a horse upon his departure was significant. This was the animal that transformed the West—and was stripped from the tribes in order to vanquish them. It was a gift that Sitting Bull treasured, along with a hat that Cody had given him as well. After Sitting Bull was killed, Buffalo Bill bought the horse back from Sitting Bull’s widows and according to some accounts rode it in a parade. And then the horse disappears from the record.

It was the legend of the dancing horse that led me into the story of Sitting Bull and Buffalo Bill, for it symbolized so much. As I thought about the steed outside Sitting Bull’s dwelling as his killing was under way, a portal into something else opened up—exactly what, I was not sure of at the time, other than the fact that here was my next story, and it was calling and at some point I would head on down its trail.

Later, as I was well along this path, I came across another image. It’s now on the cover of this book, and it too captured my attention. It was taken for publicity purposes while Sitting Bull and Buffalo Bill were on tour in Montreal, and its caption was “Foes in ’76, Friends in ’85.” I began to imagine these two men on the road, Sitting Bull on that horse, crisscrossing the nation, visiting lands that once had belonged to the Lakota, appearing as “himself ” on crowded thoroughfares that were built on top of ancient paths made by animals and the people who followed them, with William F. Cody, another mythical figure of the Great Plains, reenacting wartime scenarios that had one outcome—the end of the red man and the victory of the white—leading the whole parade in a celebration of the Wild West that became the national scripture. What were the forces that brought these two men together, I wondered, and what was the nature of their alliance? Were they each trapped in a persona, a veneer that was somewhat true? And behind the myths, the projected ideas in which they were preserved, who were they in day-to-day life? Theirs was certainly an unlikely partnership, but one thing was obvious on its face. Both had names that were forever linked with the buffalo (“Sitting Bull” refers to it, something that is not readily apparent from the name itself), and both led lives that were intertwined with it. One man was “credited” with wiping out the species (though that was hardly the case) and the other was sustained by its very life. They were, in effect, two sides of the same coin; foes and then friends, just as the photo caption said. So this image too entered my consciousness; here were two American superstars, icons not just of their era and country, but for all time and around the world. What story was this picture telling and how was it connected to the dancing horse outside Sitting Bull’s cabin?

To take a close look at these matters and find out about other underpinnings of this story, I have spent much time on the plains. I have attended memorials of the anniversary of the Little Bighorn, the infamous battle from which this country has yet to recover, in which the Lakota and Cheyenne defeated Lieutenant Colonel George Armstrong Custer and his Seventh Cavalry in 1876, leading to the round-up of remaining “renegade” Indians; the flight of Sitting Bull and his people to Canada; his ultimate return as a pariah only to be blamed for the murder of Custer and then celebrated as a brave and defiant rebel. I have visited Mount Rushmore and the Crazy Horse Memorial nearby, traveled the Badlands where the remnants of the horse tribes sought refuge after the massacre at Wounded Knee, explored the terrain of William F. Cody in Cody, Wyoming, the town that he founded and which offers visitors a stay at the Irma Hotel, named after a daughter. I have visited the site of his defunct mine in Arizona, one of the ventures near the end of his life from which he could not recover. I have communed with wild horse herds that are said to be descendants of Buffalo Bill’s horses on their home turf in Wyoming, where they flourished until recent round-ups obliterated them and their history, and I have spent time with mustang herds on a sanctuary in South Dakota where descendants of cavalry horses live out their lives, and where descendants of Sitting Bull’s horses carry on in a national park nearby and where at night, under the northern lights, you can hear the thundering hooves of the ancient steeds if you get quiet and listen for the sounds behind the winds that are forever wailing.

What divided Indians and the white man is still in play. Out on the Great Plains, a staging ground for the original cataclysm, there is a face-off in North Dakota at a place called Standing Rock, where Sitting Bull was essentially a prisoner when the land became a reservation and before that lived in its environs as a free man. An oil company wants to force a pipeline through sacred lands on Indian territory and those who first dwelled there are saying no. They fear a spill that would contaminate the waters which flow nearby—the lifeblood of us all. They have been joined by thousands of Native Americans from across the country, who arrived on foot, by canoe, and on horseback. It has been the largest such gathering of the tribes in one place in America’s recorded history, and many of these tribes are historic rivals. Regardless of the outcome at Standing Rock, one thing is certain: a shift is under way.

There was another momentous occurrence, and one that will reverberate for all time. In the frontier era, when the cavalry showed up on Indian lands, terrible things were afoot. Now, thousands of veterans had come to Standing Rock in support of Native Americans.

To celebrate this union and mark a victory against the pipeline, on December 6, 2016, at the Four Prairie Knights Casino and Resort on the reservation, descendants of soldiers who had fought in the campaigns against Native Americans knelt before Lakota elders. They were in formation by rank, with Wesley Clark, Jr., son of former army general Wesley Clark, Sr., at the forefront. “Many of us, me particularly, are from the units that have hurt you over the many years,” Clark said. “We came. We fought you. We took your land. We signed treaties that we broke. We stole minerals from your sacred hills. We blasted the faces of our presidents onto your sacred mountain . . . we’ve hurt you in so many ways but we’ve come to say that we are sorry. We are at your service and we beg for your forgiveness.” In return, Chief Leonard Crow Dog offered forgiveness and chanted “world peace” and others picked up the call. “We do not own the land,” he said. “The land owns us.”

The ceremony was marked by tears—and then whoops of joy. Outside, the winter snows began to overtake the plains and soon the veterans dispersed to the four directions.

Elsewhere, atonement and forgiveness between the white and red tribes has unfolded in a quieter manner. After a prolonged battle for course correction in the ongoing discussion of who determines American history and to what end, the U.S. Board of Geographic Names recently voted to change the name of Harney Peak in the Black Hills of South Dakota—“the heart of all there is” for the Lakota—to Black Elk Peak. This highest peak east of the Rockies was where Black Elk had his famous vision about a mythological figure known as White Buffalo Calf Woman, a dream that revealed the role of the buffalo and the horse and the four directions in the life of his people and showed how all these elements were woven together. The peak where it came to him was not the place where he had his vision (he was a young boy, at home), but the place to which his spirit traveled while experiencing it. As it happened, the site later became known to white people for something else—the Massacre at Blue Water, in which a number of Brule women and children had been killed in 1855, and it was named for General William S. Harney, who led the assault. Yet that incident didn’t happen in South Dakota. It occurred in Nebraska.

The name change is significant. Black Elk was the second cousin of Crazy Horse, and he participated in the Battle of the Little Bighorn as a young boy. Later he fulfilled the vision that transported him to that mountain peak, and he became a medicine man. His teachings were passed on in Black Elk Speaks, regarded by leaders of many denominations as one of the great works of spiritual import. When the sacred hoop of his kind had been broken, when the Great Plains were no longer limitless and the circle that linked all elements and all living things was severed, he joined the Wild West and traveled the world with Buffalo Bill. “Pahaska had a strong heart,” Black Elk said when Cody passed away, invoking the native name meaning “Long Hair” which many Lakota Indians used for both Buffalo Bill and Custer. It is a statement that many do not know or have forgotten.

In a recent ceremony to mark the transfiguration of the peak, two families gathered in a circle at a nearby trailhead. They were seventh-generation descendants of the general’s family and the family of the chief whose people were wiped out. The rite was organized by Oglala Lakota Basil Brave Heart so that members of the general’s family could apologize to members of the chief’s, and to seek forgiveness and healing. In turn, members of the chief’s family were there to publicly forgive and support the reconciliation offered by the renaming. The event had been several years in the making, involving many talks between the families, prayer walks, and facing down a range of anger and resentment in both communities. In fact, the renaming was something that few believed would happen.

When the ceremony at Black Elk Peak concluded, members of the families smoked the peace pipe and embraced, planning to continue acts of public healing between whites and Native Americans, culminating in a long-needed event at Wounded Knee. “Foes in ’76, Friends in ’85”—the slogan deployed for the partnership of Sitting Bull and Buffalo Bill—could have been the caption for a photograph of the ceremony at Black Elk Peak, with only a change of numbers. It would seem that America has embarked on the painful and necessary journey of healing our original sin—the betrayal of Native Americans. This is the fault line that runs through the national story, and perhaps the brief time that Sitting Bull and Buffalo Bill were together can serve as a foundation upon which this rift can be repaired.

And now, let us return to their final connection—the horse that Cody gave to Sitting Bull after his last performance in the Wild West. A while ago, I called Chief Arvol Looking Horse to seek his insight into this matter. He is the Nineteenth-Generation Keeper of the Sacred White Buffalo Pipe for the Lakota Indians, which was given to his people by the woman in Black Elk’s vision. He has led ceremony regarding environmental and other sacred concerns at Standing Rock, the United Nations, and elsewhere. I had met him several years earlier at a wild horse preservation event in Las Vegas; at its conclusion, everyone in attendance joined him in a prayer circle in a ballroom at the South Point Hotel, hotels and their ballrooms with garish chandeliers being the location of many such events because they are among the central gathering places of our time. “What was the symbolism of the dancing horse outside Sitting Bull’s cabin?” I asked him in our phone conversation. “Was he responding to the sound of the gunfire, as the story goes?” There was a long silence and I hesitated to break it. After a few moments, this is what he said: “It was the horse taking the bullets,” he told me. “That’s what they did.”

Not everyone believes that the horse danced. But I do. And that’s how I came to write this book, and perhaps after reading it, you’ll have your own thoughts about what happened on a winter’s dawn of 1890 and all of the matters and forces that preceded it.