1789 â George Washington proclaimed this a National Thanksgiving Day in honor of the new Constitution. He made it clear that the day should be one of prayer and giving thanks to God, to be celebrated by all the religious denominations. Abraham Lincoln established Thanksgiving as a national holiday by proclamation in 1863 when he urged Americans to set aside the last Thursday of November as a day of thanksgiving. In 1941 President Franklin D. Roosevelt signs a bill officially establishing the fourth Thursday in November as Thanksgiving Day. rochestermilitary.com
