In 1821, he was one of numerous Great Plains tribal chiefs to go to Washington, D.C. as part of the O'Fallon Delegation where they met President James Monroe.
As was their traditional practice, the Skidi Pawnee had captured an enemy girl to sacrifice her as part of the spring equinox Morning Star ceremony.
The ritual had a long tradition and the people believed that their crops and hunting would suffer if the Morning Star did not receive a human sacrificial offering.
[3]: 159 Thereby they corrected an 1818 newspaper story of a Comanche woman fleeing on a stolen horse and leaving her newborn child to be sacrificed instead.
The U.S. officials intended to impress the Natives with the power and wealth of the white man and ideally persuade them to end their warfare against American settlers.
[8] Native Americans who participated in this delegation performed traditional dances, which drew a reported six to ten thousand on-lookers.
At Miss White's Select Female Seminary, the young students begged to attend the Native American dance performance.
"[10] The BIA commissioned Charles Bird King to paint portraits of Petalesharo and others in the delegation, including Young Omahaw, War Eagle, Little Missouri and Pawnees.
During the trip, Petalesharo met author James Fenimore Cooper, who was believed to be inspired to write his novel, The Prairie.
[6]: 294 In 1827, some Pawnees, with the help of Indian agent John Dougherty, attempted to rescue a young Cheyenne girl who had been taken in a raid.
Petalesharo's story is narrated in Złoto Gór Czarnych (Gold of the Black Hills), a trilogy of novels told from the perspective of the Santee Dakota tribe, by Polish author Alfred Szklarski and his wife Krystyna Szklarska.