The federal government will investigate its past oversight of Native American boarding schools and work to “uncover the truth about the loss of human life and the lasting consequences” of the institutions, which across the decades forced hundreds of thousands of children from their families and communities, US Interior Secretary Deb Haaland announced Tuesday.

The unprecedented work will include compiling and reviewing decades of records to identify past boarding schools, locate known and possible burial sites at or near those schools, and uncover the names and tribal affiliations of students, she said.

“To address the intergenerational impact of Indian boarding schools and to promote spiritual and emotional healing in our communities, we must shed light on the unspoken traumas of the past no matter how hard it will be,” Haaland said.

A member of New Mexico’s Laguna Pueblo tribe and the first Native American to serve as a Cabinet secretary, Haaland outlined the initiative while addressing members of the National Congress of American Indians during the group’s midyear conference.

She said the process will be long, difficult and painful and will not undo the heartbreak and loss endured by many families.

Starting with the Indian Civilization Act of 1819, the United States enacted laws and policies to establish and support Indian boarding schools across the nation. For over 150 years, Indigenous children were taken from their communities and forced into boarding schools that focused on assimilation.

Read the full article about Indigenous boarding schools in the U.S. at Al Jazeera.