A historic tomahawk on display at Harvard University is now at the center of a conversation over who morally should own it.

The more than 150-year-old artifact once belonged to Ponca Chief and Native American Civil Rights Leader Standing Bear.

"All I'm doing is making a simple appeal to their morality," said Brett Chapman, a Tulsa attorney.

Bret Chapman is one of Standing Bear’s descendants and says the tomahawk should be returned to the Ponca Tribe.

Last month, Chapman wrote a letter to Harvard's Peabody Museum of Archaeology and Ethnology, where it's now on display.

We're in this time in our history where we're beginning this reconciliation with our own history, different viewpoints, different races, different cultures,” said Chapman. “This tomahawk is very important to Ponca culture and Ponca history."

Chapman says that history dates back to the late 1800s.

The Ponca tribe was forced from their native Nebraska to present-day Oklahoma, but after several members of his family died, Standing Bear left the reservation to go back north, defying the US Government - and was arrested.

That arrest ultimately led to a landmark federal civil rights decision.

“When he won, he had these two attorneys that represented pro bono…Standing Bear is so grateful, he gifts both of them with tomahawks, a headdress," said Chapman.

One of the attorneys though eventually sold the tomahawk, which ended up at Harvard.

"They may have some legal right to it, but the moral right I don't think they have," said Chapman.

News on 6 reached out to Harvard for a comment, but have not heard back.

Chapman says though, he has had productive conversations with the University.

He's optimistic that both sides will come to an agreement