The U.S. Conference of Catholic Bishops issued a formal apology on Friday for the church’s role in the mistreatment and trauma experienced by Native Americans in the United States, notably in church-operating boarding schools that sought to force the assimilation of Native children into American culture.

Starting in the 19th century, hundreds of thousands of Native children were removed from their families and sent to the schools, where they often faced abuse, neglect and hard labor. Of the…