AMNA NAWAZ: For 150 years, the U.S. government sent Native American children to remote so-called boarding schools as part of a systematic effort to seize tribal lands and eradicate Native American culture.

Dozens of these boarding schools were run by the Catholic Church or its affiliates.

A new Washington Post investigation has revealed widespread sexual abuse of generations of these children at many of those institutions.

Lisa Desjardins has the story.

And a warning: The story contains sensitive subject material.

LISA DESJARDINS: Geoff, this report documents the sexual abuse of more than 1,000 children by over 100 priests, sisters and brothers.

But experts believe that number is likely a significant undercount.

Earlier today, we spoke with Deborah Parker, chief executive of the National Native American Boarding School Healing Coalition.

DEBORAH PARKER, National Native American Boarding School Healing Coalition: For us, this is a national crime scene, and our relatives, our Native American relatives, deserve to know the truth.

LISA DESJARDINS: For more, we're joined by Washington Post reporter Dana Hedgpeth, who was part of the team that reported this story and is a member of the Haliwa-Saponi Tribe of North Carolina.

Thank you so much for joining us.

Can you help our viewers understand the scope of the abuse that you uncovered?

DANA HEDGPETH, The Washington Post: This is a very important topic, and there's been a lot of work already done on this.

We hope to move the ball forward and shed new light on it.

And what we found in our investigation gave new details about the level of sexual abuse that was done by Catholic priests, sisters and brothers from the 1800s to the 1900s at schools.

Most of the abuse occurred in the 1950s and '60s and involved 1,000 children.

And experts like Deb Parker and others believe that that is really only the tip of the iceberg, that the abuse was more widespread, deeper than probably we found.

But documents are inconsistent and incomplete.

So that is what we found in our investigation.

LISA DESJARDINS: We're talking about Native boys and girls ranging from age from some of the very smallest into teenage years, some generations, multiple generations at the same school by multiple abusers.

Deborah Parker also spoke to us about why some of those survivors stayed silent so long.

DEBORAH PARKER: Many of these boarding schools' survivors were told that, if they tell anyone, that they'd be hurt, or that God wouldn't love them, or that they would actually go to hell.

There's a great fear in telling the story.

LISA DESJARDINS: This speaks to one of the evils of this kind of abuse.

But reporters have talked about - - in the national spotlight, we have had a conversation about Catholic abuse of children for decades now.

Why do you think it's taken so long to pay attention to what happened in Native land?

DANA HEDGPETH: Folks like myself, Native Americans, know these stories, they have been passed down.

And families, people know these stories.

It is not a new history, unfortunately.

It's a painful history that's been recognized.

Probably one of the best reasons that this history is coming more to light now in more recent times is twofold.

One, in the early 2000s, The Boston Globe did great work of exposing the abuse that was happening there.

So that showed people that, the Catholic Church, people could be held accountable.

And that was a very much a turning point for Native Americans.

These were very young children.

They didn't know at the time or understand that they were being abused.

And the way abuse happens, unfortunately, it takes so long to process.

It's painful.

People repress those things.

And only as they became adults did they really understand and feel more comfortable with coming forward.

LISA DESJARDINS: There are so many gut-wrenching stories here that are important to tell.

But could one stand out of a person or family that you think viewers should be aware of?

DANA HEDGPETH: I would say Clarita Vargas, who went to a school, a Catholic-run school, in Omak, Washington.

And Clarita came forward, and she was one of several dozen victims in a large lawsuit that eventually got settled.

But what really stands out with Clarita's stories that the lawyers noticed right away is the movie nights, as the lawyers always called it.

Clarita went there when she was a young girl.

And, sadly, she was lured, like many children.

A priest named Father Morse would invite them to his office on Sunday nights for movie night.

And if you can imagine being a young child and being lured to see a movie, they didn't have any special things, but being lured with candy canes at Christmastime or chocolate bars or chocolate chip cookies, where the children were then abused.

And, sadly, what's so powerful about that story is it wasn't just happening to Clarita.

It was happening to the other young girls at that same school.

And then, as the lawyers investigated and went to other reservations, talked to other people, they realized that this similar thing, luring children with candy, literally preying on children, these vulnerable kids away from their homes, taken from their families, stripped of their culture.

And it was a pattern of abuse that was happening, just not at this school, but at dozens of other schools.

LISA DESJARDINS: We also spoke to someone else in your story, Jim LaBelle.

He's Inupiaq of Alaska.

And he was separated from his family, not even given a name, called by a number when he was a child, he told us, sexually abused and beaten.

Here's how he described the isolation, especially from that abuse.

JIM LABELLE, Boarding School Survivor: There is no place that a child could be safe from predators, pedophiles, from so much abuse, strappings, rippings, beatings, putting in dark closets, wearing a dunce cap in the front of the classroom, running the gauntlets.

There is no place to get away from any of what we were experiencing.

LISA DESJARDINS: This is so shameful.

No White House has ever formally apologized for the United States' integral role in what happened in boarding schools in this country.

Now, the U.S. Conference of Catholic Bishops, responding to your story, did acknowledge the history and deep sorrow from this era.

They said they hope for a dialogue.

Didn't talk about the sexual abuse in their response, though.

My question to you is, what do Native communities and survivors want to happen?

What do they want to hear?

DANA HEDGPETH: It's not about the money from lawsuits.

It's not about issuing press releases by Catholic dioceses or churches.

For so many Native people, survivors who went through these schools and their descendants, it's about the acknowledgement that they were wronged.

It's about someone of official capacity, the president, the pope, standing before them and saying, I'm sorry.

This government wrong you.

It was a systematic effort to try to eradicate and assimilate Native children, strip them of their culture and what they knew, force them into a -- quote, unquote -- "education."

And they want that acknowledgment.

They want that face-to-face acknowledgment, not on a piece of paper.

They want that face-to-face acknowledgment that they were wronged by the U.S. government.

LISA DESJARDINS: Your address is also sort of an acknowledgement.

It is from a survivor of the boarding schools as well.

I want to ask you, in thinking about this story, why do you think it is so hard for the United States, versus Canada, which has spent much more looking into these issues and compensating survivors?

Why is it hard for the United States to reckon with these very dark moments in our past?

DANA HEDGPETH: It's a very good question, and I like the way you asked that.

I would say Canada struggled as well.

We talked to Murray Sinclair, who headed the Truth and Reconciliation Commission there in Canada, in quite a bit of detail.

And he told us that it was difficult there.

This is not an easy process any time you shine a light on a tragic history.

This is the darkest chapter of America's very dark history of how Native Americans were treated.

So there is nothing easy about this.

They spent seven years in Canada and $6 billion to come to a 4,000-page conclusion of how their indigenous communities were treated, and they concluded that it was a cultural genocide.

Why is the U.S. so far behind?

Again, it's not an easy process.

I think things are moving forward.

It is coming into the light, so to speak, in large part because of Deb Haaland, who is the first Native American Cabinet secretary.

It's a very personal story for her, her own family.

Her own grandmother was taken, rounded up on, put on a train, taken 100 miles from her home.

No one understands this story more personally than Deb Haaland.

And she's bringing it to light.

LISA DESJARDINS: Dana Hedgpeth, thank you so much.

This is phenomenal reporting and so important.

DANA HEDGPETH: Thank you so much for having me and for listening to the story.