Thanksgiving, or Thanksgiving Day, is a holiday celebrated in the United States on the fourth Thursday in November. It has been celebrated as a federal holiday every year since 1863, when, during the Civil War, President Abraham Lincoln proclaimed a national day of "Thanksgiving and Praise to our beneficent Father who dwelleth in the Heavens", to be celebrated on the last Thursday in November. Thanksgiving was also celebrated nationally in 1789, after a proclamation by George Washington. As a federal and public holiday in the U.S., Thanksgiving is one of the major holidays of the year. Together with Christmas and New Year, Thanksgiving is a part of the broader holiday season. (excerpt from Wikipedia)
Here's a little after dinner treat for your pleasure...
http://images.businessweek.com/ss/05/11/egreetings/image/01.swf
Happy holidays!