This number of immigrants called Pilgrims became the first people to settle in America, establishing New Plymouth. But unbearably hungry through a cold Winter in the new land, half of the migrants died. By the spring of the following year, 1621 they were in contact with the Wampanoag Indians and they were helped by the Aboriginal people in planting crops, fishing and hunting. In October, after the first harvest, Pilgrims leader William Bradford organized an Thanksgiving festival, invited the Wampanoag Indians to the party, and this was the beginning of the tradition. Thanksgiving of the United States.