Between 1828 and 1970, 3,104 Indigenous American children died at boarding schools run under policy to separate them from culture and assimilate into white society, a Washington Post investigation has found.
It's more than three times the figure documented in a federal government report earlier this year.
In July, the United States Department of the Interior's Federal Indian Boarding School Initiative Investigative Report second volume was 'confirmed' "that at least 973 American Indian, Alaska Native, and Native Hawaiian children died while attending Federal Indian boarding schools" after assessing "approximately 103 million pages of U.S. Government records".
The report also updated the official list of Federal Indian boarding schools to include 417 institutions across 37 states or then-territories, also acknowledging an additional 1,025 similar institutions "used to advance similar assimilation and education policy goals".
It also stated "there are at least 74 marked and unmarked burial sites at 65 different school sites" and the Federal Indian boarding school system were implicated by over 100 Indian Tribes-United States Treaties.
On Monday, the Washington Post reported more than 800 of the 3,104 children were never returned to their families, instead buried at or near the boarding schools they attended, following a year-long investigation.
They also reported an additional documented 66 cemeteries in addition to the Government's figured.
The outlet claims they drew on hundreds of thousands of government documents in their investigation.
These records were also said to outline the harsh punishment and treatment of the children in the boarding schools.
"These were not schools," Nebraska Commission on Indian Affairs executive director Judi Gaiashkibos told Washington Post.
"They were prison camps. They were work camps."
Cause of death was reportedly able to be determined for around half of the 3,104 children across 202 schools.
Infectious diseases, most commonly tuberculosis, accounted for 1,156 deaths.
The Outlet found 14 died from poisoning, 15 died while running away, 26 drowned and 99 by "suicide, accidental, and other".
Interior Assistant Secretary for Indian Affairs Bryan Newland said the government's work so far "did not tell the complete story of the trauma of the federal Indian boarding school era" as a result of limitations to official government documents.
"These schools were used to pursue a policy of forced assimilation over a century and a half. Our work has occurred over just three years," he told Washington Post.
"Others must carry this work forward", Mr Newland reportedly added, "What we've done over the past few years isn't the end of the story.
The Department of the Interior's July report made eight recommendations, including; Invest in Remedies to the Present-Day Impacts of the Federal Indian Boarding School System; Build a National Memorial; Identify and Repatriate Children who Never Returned from Federal Indian Boarding Schools; Return Former Federal Indian Boarding School Sites; Tell the Story of Federal Indian Boarding Schools; Invest in Further Research and; Advance International Relationships.
"The US government could strengthen engagement with other countries with their own histories of boarding schools or other assimilationist policies, including Canada, Australia, and New Zealand to exchange best practices for healing and redress between Federal governments and Indigenous governments for Indigenous child removal through boarding schools and predatory foster care and adoption practices," the report recommended.
"To further this goal, the US should expand capacity, including through the Department's Bureau of Indian Affairs (BIA), to support engagement on international Indigenous issues. To strengthen the US government's expertise on Indigenous issues globally and connections with other countries, the US government should establish an ambassador position focused on engagement on international Indigenous issues."
The report also recommended the Government 'Acknowledge, Apologize, Repudiate, and Affirm', including a formal apology and acknowledgment "of its role in adopting a national policy of forced assimilation of Indian children, and carrying out this policy through the removal and confinement of Indian children from their families and Indian Tribes and the Native Hawaiian Community and placement in the Federal Indian boarding school system".
Outgoing US President Joe Biden issued a formal apology in October.
In 2022, Pope Francis apologised for the Catholic Church's role in the historic abuse of Indigenous Canadian children in the country's residential schools.
There have been strong calls in Australia for similar acknowledgement by the Catholic Church in relation to the treatment of First Nations children.
