Nine Native American children finally came home to their Dakota soil recently.

Their remains were returned to the Rosebud Lakota Sioux reservation in South Dakota after these children were forcibly removed from their tribal homes in 1880 and shipped away to a boarding school in Pennsylvania. And there, 1,400 miles away, they had rested for 140 years, practically forgotten by all but a few remaining family members back at their tribal homeland.

Their lives completed a bittersweet circle last week. Friday’s burial ceremony was preceded by a solemn caravan that carried the remains from Sioux City through Santee, Nebraska, and Pickstown. Many people lined the way to pay their respects to the nine children, who were mourned and celebrated

Victims of a brutal policy, they were not nameless. They were Lucy Take the Tail (Pretty Eagle), Rose Long Face (Little Hawk), Ernest Knocks Off (White Thunder), Dennis Strikes First (Blue Tomahawk), Maud Little Girl (Swift Bear), Friend Hollow Horn Bear, Warren Painter (Bear Paints Dirt), Alvan (Kills Seven Horses) and Dora Her Pipe (Brave Bull).

The burials brought closure for these souls, but the history to which they are tragically tied remains a mystery to the broader population.

Beginning in 1789, the U.S. military began rounding up tens of thousands of Native American children and shipping them off to boarding schools to be reeducated. These assimilation efforts included forcing children to cut their hair, give up their culture, speak only English, wear school uniforms and become indoctrinated in Christianity. Many of the abducted children – and that is the proper adjective for it – survived this trauma, but thousands (one researcher put the number at nearly 40,000, according to Reuters) did not, dying of abuse and disease. Several thousand of these children are believed to remain missing to this day.

Among those schools involved in this practice was the Carlisle Indian Industrial Boarding School, an icily named institution that one media report referred to as the “flagship” of this boarding-school system until the school closed in 1918. That’s where those nine kids from Rosebud were sent and it’s where they died.

This story is not unique to America’s “conquest” of the frontier and our sense of Manifest Destiny.

Canada is also grappling with this tragic history, confronting a practice that began in 1831 and was carried out until as recently as 1996, according to Reuters. These children were subjected to abuse and neglect in what Canada’s Truth and Reconciliation Commission in 2015 deemed “cultural genocide.” In the last few months, the bodies of more than 1,500 indigenous children have been found on the grounds of seven former boarding schools in Canada, according to NBC News. It’s likely that more graves with many more remains exist.

And “cultural genocide” is the correct term for this crime: It was an effort to erase what these children were, to “European-ize” them and to extinguish the indigenous culture across vast parts of this continent.

This is a past that cannot be forgotten or dismissed as a relic from another time. Our history is woven into the fabric of who we are now.

We owe it to the victims and those family members who mourn them, and we owe it to all people of both the U.S. and Canada, to confront and understand this dark, vague chapter in our history, which must not remain buried and unmarked in the past.

“We must uncover the truth about the loss of human life and the lasting consequences of the schools,” Secretary of the Interior Deb Haaland vowed recently.

“The truth is coming out,” Steve Moose, a blood relative of one of the nine, told the Press & Dakotan last Friday in Santee, “and people understand what happened.”

This grim but necessary process of unearthing (literally) the truth has only just begun.