Watch VoirFilms. William Bradford fled with the Pilgrims to the new world, where he discovered that the price for religious freedom was hunger, sickness and death. As a peacemaker, he befriended the Native Americans who taught the struggling Pilgrims how to survive. By the end of the first year, William Bradford became Governor of the new land. After their first critical harvest, he set aside time for the Pilgrims and their new Native American friends to feast together and express their thanks to God. Thus, William Bradford became the Father of Thanksgiving Day.