President Biden plans to issue an official apology for a U.S. policy that for 150 years sent Native American children to boarding schools where they were stripped of their culture and language.   A source familiar with the plans said the apology will happen Friday as Biden is set to have his first diplomatic visit to a tribal nation as president.   He will be giving a speech at the Gila River Indian Community in Arizona, highlighting the steps he has taken to invest in tribal nations and strengthen relationships with those communities. It is the first time a president would apologize for the actions of the U.S. government from 1819 to 1969 as tens of thousands of Native children were ripped from their homes and sent to these boarding schools by those who hoped they would assimilate into white culture.   The Department of the Interior recently revealed in an investigation that almost 1,000 Native children were killed at these schools due to starvation or disease, and others were physically or sexually abused.  The department has also uncovered more than 60 grave sites among the more than 400 boarding schools that were discovered.   “It’s extraordinary that President Biden is doing this,” Interior Secretary Deb Haaland, the country’s first Native American Cabinet secretary, told The Washington Post. “It will mean the world to so many people across Indian Country.”