President Biden on Friday issued a formal presidential apology to Native American communities for the atrocities committed against Indigenous children and their families during a 150-year era of forced federal Indian boarding schools. The president chose to speak at the Gila River Indian Community in Arizona, although he apologized to all tribal nations for their generations of suffering.

"After 150 years, the United States government eventually stopped the program," the president said. "But the federal government has never, never formally apologized for what happened — until today. I formally apologize, as president of the United States of America, for what we did. I formally apologize. That's long overdue."

From 1819 through the 1970s, the federal government and religious institutions established boarding schools throughout the country to assimilate Alaska Native, American Indian and Native Hawaiian children into White American culture by forcibly removing them from their families, communities and belief systems. The president called the practice "one of the most horrific chapters in American history" and a "sin on our soul," holding a moment of silence for the lives lost.

"Generations of Native children stolen, taken away to places they didn't know, with people they'd never met, who spoke a language they had never heard," Mr. Biden said. "Native communities silenced. Their children's laughter and play were gone. Children who would arrive at schools, their clothes taken off, their hair that they were told was sacred, chopped off. Their names literally erased, replaced by a number or an English name."

Many children who attended these boarding schools endured emotional, physical and sexual abuse, and hundreds of them died. And for those who did return home, they were wounded in body and spirit, Mr. Biden said. Even after the Civil Rights Act was passed in 1964, the atrocities continued.

"I say this with all sincerity — this, to me, is one of the most consequential things I've ever had the opportunity to do in my whole career as president of the United States," Mr. Biden said of his presidential apology. "It's an honor, a genuine honor, to be in this special place on this special day."

The history is personal for Interior Secretary Deb Haaland, the United States' first-ever Native American Cabinet Secretary. Her maternal grandparents were 8 years old when they were taken from their communities and placed in a Catholic boarding school until they were 13, and her great-grandfather was also forced into an Indian boarding school.

"Tens of thousands of Indigenous children as young as 4 years old were taken from their families and communities and forced into boarding schools run by the U.S. government and religious institutions," Haaland said Friday in Arizona. "These federal Indian boarding schools have impacted every Indigenous person I know. Some are survivors, some are descendants. But we all carry the trauma that these policies and these places inflicted. This is the first time in history that a United States Cabinet secretary has shared the traumas of our past, and I acknowledge that this trauma was perpetrated by the agency that I now lead."

Haaland conducted the first-ever federal investigation into the Indian federal boarding school era. The probe revealed that more than 500 American Indian, Alaska Native and Native Hawaiian children's deaths occurred at 19 of the federal Indian boarding schools, and identified 53 marked and unmarked burial sites at school sites nationwide.

The Interior Department's report found that when children failed to meet standards or broke rules, they were subjected to corporal punishment, including "solitary confinement; flogging; withholding food; whipping; slapping; and cuffing." Oftentimes, older children were forced to inflict punishment on their younger classmates.

The federal government often contracted with Presbyterian, Catholic and Episcopalian religious institutions to run the schools, in an effort to assimilate Native children into White American culture.

"But as we stand here together, my friends and relatives, we know that the federal government failed," Haaland said, to applause. "It failed to annihilate our languages, our traditions, our life ways, it failed to destroy us, because we persevered."

Speaking with reporters aboard Air Force One en route to Arizona, Haaland's voice broke.

"For decades, this terrible chapter was hidden from our history books," Haaland said Thursday. "But now, our administration's work will ensure that no one will ever forget."