Thanksgiving could be defined as the one truly "open" American holiday. I get sappy around Thanksgiving because it has always represented the best of America for me - freedom, opportunity, thankfulness. It is the least commercial of all our holidays and centers around family and friends without any specific religion or ritual. There are no gifts required - just company and conversation.
Thanksgiving is the one holiday that everyone celebrates. As a kid growing up orthodox in Brooklyn, I spent many holidays with friends and immediate family but distance and different observance levels often kept extended family apart on holidays. Thanksgiving was the one holiday that brought us all together as a family and a country - no matter race, religion or creed.
It is the one time that we put aside differences and allow for everyone to participate as they see fit and contribute in their own way. There was a time when Memorial day and Veterans day and even July 4th had similar contexts - but they have been lost in sales and shopping and devalued to long weekends at the beach.
Thanksgiving is the one remaining event every citizen participates in as they see fit. The holidays' roots are religious in nature but the ritual(s) associated with it are open and therefore enable everyone to participate and put there own stamp on it.
Thankfulness is a universal human emotion.
[Note: If you like the image - go check it out on flickr it has some great notes over each of the photos]
