Here are some interesting things that have been wrongly portrayed about the pilgrims.
You have probably seen the typical pilgrim picture: buckles on hats and shoes, man carrying a blunderbuss (a short-barrelled bell-mouth gun), and log cabins.
In reality, buckles as decorations didn't appear until later in the 17th century, not earlier when the pilgrims arrived. Women didn't wear bangs, or hair down loose. Men would have had a full beard, not Amish beards (without a moustache).
The log cabin method of home building was brought to America by Swedish colonists in 1638, many years after the pilgrims. The blunderbuss was a riot gun used for dispelling crowds, not hunting. And it would not have been with the pilgrims, as it was a gun used in the 1700s.
Go check out a typical picture and see what errors you find! :-)
(Most of this information was taken from The Thanksgiving Primer.)