Image copyright Getty Images Image caption David Johnson’s father — Col. Stephen Johnson — played a key role in the Cheyenne/Arapaho wars
The great-grandson of the Lakota leader known as Lakota Sioux Warrior Sitting Bull has been identified using DNA and facial recognition techniques.
BBC News asked Smithsonian Institution anthropologist David Johnson to identify the identity of the sixth-great-grandson.
He believes the person is David Johnson.
The younger Mr Johnson grew up at his family’s Indian Residential School in Maine and attended Kennebec College in South Portland in 1971.
He later returned to the country where he studied anthropology and eventually enrolled at the University of Wisconsin in Madison in 1981.
He says his work helped lay the foundations for the documentary Blood Brother, an award-winning movie about his grandfather’s life.
“Of course he knew he was Indian, but he didn’t realise how important it was for all Americans,” he says.
Image copyright Getty Images Image caption David Johnson is the nephew of Lakota Lakota Warrior Sitting Bull
His cousin Francis Johnson, who is also a retired University of Wisconsin professor, says his uncle is a staunch advocate for historic research.
“He feels that just because it’s a celebrity isn’t the right reason to study history in a selective manner,” he says.
“If you’re passionate about history you have to be proud of it and even more, you have to do something.”
Mr Johnson’s most recent project is having DNA profiles of American Indians and Asians sequenced and analysed.
He says he is exploring how these results might help first and second generation Native Americans.
DNA sequencing involves splitting a person’s DNA into two and then returning the duplicate DNA into a single drop of blood.
Image copyright Getty Images Image caption The Oglala Sioux tribe are based in South Dakota, where the settlement of the area dates back 3,000 years
“Any of these people would become free,” he says.
“If a child were to be born, Native Americans could then decide if it’s time for them to become part of the mainstream. It will allow the four or five tribes in the region to play a vital role in the future.”
There are more than 200,000 Native Americans – living in 13 states and the District of Columbia – living among Asian Americans.
Mr Johnson aims to have more than 1,000 DNA samples analysed before the end of 2019.
“What about those of us from Native American family members? We are living in the future, or we may be among the very first survivors.”
It was 15 years ago that he and his cousin won a grant of more than $75,000 (£55,000) from the US government, under the Native American Graves Protection and Repatriation Act.
Mr Johnson worked for two years on the report, which was dedicated to his late aunt and uncle.
“My great-grandfather was asked to leave the Reservation, his brother came with him, and they went to Canada, where they engaged in massive war in the North West Territories,” he says.
Mr Johnson’s father, Col. Stephen Johnson, served in World War II and later played a key role in the Cheyenne/Arapaho wars.
He is a member of the Oglala Sioux tribe in South Dakota, and has remained active in historical research and efforts to return ancestral remains to their ancestral lands.
“Stephen is a tremendous part of the equation. He’s been working for 65 years trying to solve this problem. His goal has always been to heal the wounds between Indians and the West.”
Image copyright Getty Images Image caption David Johnson pictured with his family at the movie premiere of ‘Blood Brother’ in 2007