By: News On 6 TULSA, Oklahoma - 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.