Harry Truman actually said...
Now, Therefore, I, Harry S. Truman, President of the United States of America, in consonance with the joint resolution of Congress approved December 26, 1941, designating the fourth Thursday of November in each year as Thanksgiving Day, do hereby proclaim Thursday, November 25, 1948, as a day of national thanksgiving; and I call upon our citizens to observe that day by giving thanks to Almighty God for the bounties which have been bestowed upon our Nation and by resolving to render generous assistance to the hungry and homeless in other lands, thus renewing our devotion to the cause of good-will among men.
11/11/1948