The Sun Dance was a staple of Plains Indian culture during the 19th Century. The four-day prayer event required a year of preparation. It was aimed at celebrating the gifts of the Great Spirit and seeking His protection and favor for the coming year. It’s probably best-known because some male dancers were connected by a thong to a center pole—and the thong was implanted in their chests using bone. By the end of the ceremony, the bone was ripped out.
In the mid 1880s, the federal government banned the dance. It was reinstated in the 1970s.