A food historian outlines which items were probably on or off the menu at the first Thanksgiving:
Ham: There is no evidence that the colonists had butchered a pig by this time, though they had brought pigs with them from England.
Sweet Potatoes/Potatoes: These were not common.
Corn on the Cob: Corn was kept dried out at this time of year.
Cranberry Sauce: The colonists had cranberries but no sugar at this time.
Pumpkin Pie: It's not a recipe that exists at this point, though the pilgrims had recipes for stewed pumpkin.