Our modern Thanksgiving menu is based on the offerings of the first celebration in Plymouth, Massachusetts. Beer was there. A foul water supply was the rule of the day, and beer was the beverage of choice.
Beer is brewed with boiling water, thus killing disease-bearing microbes.
When the 100-plus Pilgrims and crew set sail, beer was a precious and vital cargo, both healthy nourishment and a comforting reminder of home. They were out of beer. Samoset and his tribe taught the settlers agriculture and fishing skills and the concept of fertilizing, using decaying fish buried in the ground to enhance the growth of crops of corn and barley, which were used to brew beer. In fact, a brewhouse was one of the first structures built in the new world. The fall harvest of 1621 was successful enough and the Pilgrims put away enough food for winter that Pilgrim leader William Bradford declared a day of Thanksgiving to celebrate.