To be honest I have a horrible memory and have been out of elementary school for so loooong! I kid- I am 30 years old but it does seem like forever ago and now have children in Jr. High. Lets see if I think back on just growing up in the U.S and what I can actually remember about what was taught about the first Thanksgiving.
From the little bit I can remember (and to be honest some quick internet research to refresh my memory) the first Thanksgiving was a gathering of the Native Americans and Pilgrims to share a bountiful harvest. The pilgrims who settled at Plymouth Rock the year prior had a hard time with their crops and lives were lost. The Native Americans helped the pilgrims with their crops; this was thought to be the reason they survived. Due to this they had a feast to celebrate their bountiful harvest.
I do not remember specifically but since I have children who have recently completed elementary school I will guess that we colored, drew or assembled a Turkey, Native American, Pilgrim, the Mayflower, and the food scenes.