Thanksgiving Day, the third Thursday of each November, is a national holiday in America; a holiday officially pronounced by the President each year.
The thanks (originally thanks for a bountiful harvest) go to whomever each person perceives as being the giver of all things good. Traditionally God, but I see no reason why one could not give thanks to the universe or Goddess, whatever.
Presents are not normally given but Hallmark, et al, has seized this day as another marketing opportunity and you will now find in the stores a wide array of Thanksgiving cards. (Stay tuned. Another ten years and it will have become another 6 week extravaganza.)
Over the years a certain sort of decoration has come to denote Thanksgiving. For instance, a turkey, whether live or on paper or a ceramic figure, is a symbol of Thanksgiving. So are cornucopias overflowing with harvested vegetables and fruits, as are paper tablecloths decorated with autumn colors.
I know Canada has a Thanksgiving Day too. How does it differ from the US version? Anybody?