Dear Steven,
Yes, it's true that I knew you knew!
We of "Canuckistan" once celebrated Thanksgiving together with you.
But then it was moved to October.
At least we have more time to get over the Thanksgiving turkey before Christmas!
As you know, "Thanksgiving Day" was only established as a regular, harvest-festival recently.
It was formerly the prerogative of the King (when you guys were Royal Colonies

) to establish Thanksgiving Days - often at his whim and fancy.
A Thanksgiving Day was proclaimed when Lord Admiral Nelson won his victory over Napoleon, as an example.
If I'm not mistaken, I think you Americans really honour Thanksgiving Day in a way no one else does.
Perhaps, as far as secular holidays goes, it is of even more significance than or equal to that of Christmas?
Alex