Was 1621 the first Thanksgiving

Actually, no, it wasn't. In this period of time, many thanksgivings were held. These celebrations were held to thank God for a certain event that has occured, such as the winning of a battle, or a bountiful harvest. However, if you would like to be specific, it was the first Thanksgiving held in the Americas for a bountiful harvest. Other small Thanksgivings were held before by European Explorers for numerous reasons.