Thanksgiving is an annual one-day holiday where we give thanks for the things one has at the end of the harvest season. In 1621 the Pilgrims started the tradition while they were particularly thankful for Squanto, the Native American who that them how to catch eel and grow corn. Without Squanto the Pilgrims would not have survived in the new world. After the Pilgrims first harvest they were especially thankful they were still alive and want to celebrate this.