An initial investigation commissioned by Interior Secretary Deb Haaland documented some of the atrocities that Native American children faced at over 400 boarding schools that the federal government forced them to attend between 1819 and 1969. Ms. Haaland described the inquiry as a first step toward addressing the policy’s “intergenerational trauma.”

An Interior Department report issued on Wednesday detailed the abuse of many children at government-run schools, including beatings, food deprivation, and solitary confinement. It also discovered burial grounds at more than 50 of the former schools, a figure that the department expects to grow as the investigation continues.

The report is the first step in a comprehensive review announced in June by Ms. Haaland, the first Native American cabinet secretary, following the discovery of hundreds of unmarked graves of children who attended similar schools in Canada, which sparked a national reckoning there.

“Approximately 19 federal Indian boarding schools accounted for over 500 American Indian, Alaska Native, and Native Hawaiian child deaths,” according to the initial investigation. According to the report, this figure is expected to rise.

From 1869 to the 1960s, hundreds of thousands of Native American children were removed from their homes and families and placed in boarding schools run by the government and churches.

According to the National Native American Boarding School Healing Coalition, there were 20,000 children at the schools in 1900; by 1925, the number had more than tripled.

Following the discovery of 215 unmarked graves in British Columbia and 750 more in Saskatchewan last year, Ms. Haaland announced that her organization would search the grounds of former schools in the United States and identify any remains. Such schools were attended by Ms. Haaland’s grandparents.

“The consequences of federal Indian boarding school policies, including the intergenerational trauma caused by family separation and cultural eradication inflicted upon generations of children as young as four years old,” Ms. Haaland said in a statement. “It is my priority to not only give voice to the survivors and descendants of federal Indian boarding school policies, but also to address the lasting legacies of these policies so Indigenous peoples can continue to grow and heal.”

Bryan Newland, the agency’s assistant secretary for Indian affairs, wrote the 106-page report, which concludes that more research is needed to better understand the long-term effects of the boarding school system on American Indians, Alaska Natives, and Native Hawaiians. According to the report, assimilation was only one of the system’s goals; the other was “territorial dispossession of Indigenous peoples through the forced removal and relocation of their children.”

The government has yet to provide a forum or opportunity for survivors, descendants of survivors, or families of survivors of the boarding schools to describe their experiences at the schools. To assimilate Native American children, schools gave them English names, cut their hair, and prohibited them from speaking their native languages or practicing their religions or cultural traditions.

Ms. Haaland also announced a year-long cross-country tour called The Road to Healing, during which survivors of the boarding school system will be able to share their stories.

The Canadian government has launched similar efforts, allocating approximately 320 million Canadian dollars for communities affected by the boarding school system, burial site searches, and victim commemoration.