Thanksgiving day is celebrate on fourth Thursday in November and many countrys celebrate this feast. In this day people thanks God for their food..... American Thanksgiving was celebrated in 1621, to commemorate the harvest reaped by the Plymouth Colony after a harsh winter. In this winter many people die of hungry, disease and cold. In that year Governor William Bradford proclaimed a day of thanksgiving. The colonists celebrated it as a traditional English harvest feast, to which they invited the local Wampanoag Indians.