Happy Thanksgiving to all of my American visitors!
Thanksgiving, also known as Thanksgiving Day, is a harvest festival. Traditionally, it is a time to give thanks for the harvest and express gratitude in general. It is primarily a North American holiday which has generally become a national secular holiday with religious origins.
The dates and whereabouts of the first Thanksgiving celebration are a topic of modest contention. Though the earliest attested Thanksgiving celebration was on September 8, 1565 in what is now Saint Augustine, Florida[1][2], the traditional “first Thanksgiving” is venerated as having occurred at the site of Plymouth Plantation, in 1621.
Today, Thanksgiving is celebrated on the second Monday of October in Canada and on the fourth Thursday of November in the United States. Thanksgiving dinner is held on this day, usually as a gathering of family members.
More info on Thanksgiving can be found on Wikipedia.