The date of the feast is unknown. However, it must have occurred previously to December as that is the month that one of the only written accounts first is documented. There are only two known written eyewitness reports of the event; that of Edward Winslow and William Bradford who described the details of the fishing and hunting expeditions and the fact that the festivities lasted three days.
The Massasoit, ninety individuals in totem, provided five deer for the feast. Among some of the other edible items were duck, geese, turkey, fish, and corn. It is unlikely that the dishes presented were extravagant because the colonists weren't aware when the next ship docking would take place and would have conserved whatever spices they had.
There are many myths surrounding the modern day celebration of Thanksgiving. Although Thanksgiving as a holiday can be traced to the harvest celebration of 1621, it was neither a feast held annually or meant as a celebration of giving thanks. Just two years later, in 1623, there is no mention of a Thanksgiving feast.
The Pilgrims were primarily a Separatist group who arrived in Massachusetts the previous year. Their visual use in Thanksgiving decorations is often misconstrued. The familiar black and white garb with the large buckles that we see today is incorrect. The appearance is related to Puritans who arrived in the Americas later and who only used the black and white garb occasionally. Buckles weren't in production until the late 1600's as well.
When a member of the Mayflower party would die, an inventory of their belongings would be assessed. Most inventories revealed a tendency for darker colors, but many people had a wide range of color in their clothing collections.
The Pilgrims weren't the only ones misrepresented in latter day artwork and stories. The Massasoit are typically depicted in costumes that are more closely related to Plains tribes.
The first national Thanksgiving was declared in 1777 by the Continental Congress. It wasn't yet an observed holiday and several other "Thanksgiving" days were proclaimed inconsistently until 1815. Thanksgiving reverted to being a regional event until 1863 when two days were declared. The first being August 6th after the victory at Gettysburg and the second being the first last-Thursday-in-November celebration.