George Washington issued the first national Thanksgiving proclamation in 1789.
On October 3, 1789, Washington proclaimed a national day of public thanksgiving and prayer. The proclamation followed a request from Congress and called on Americans to acknowledge what it described as the nation's blessings, including peace, prosperity, and the successful establishment of a constitutional government.
The day was observed on Thursday, November 26, 1789. Washington issued it from New York City, which was then the temporary national capital. The proclamation was not the origin of every Thanksgiving tradition in North America; communities had held harvest and thanksgiving observances long before the federal government existed.
The modern federal Thanksgiving holiday developed much later. Abraham Lincoln issued a proclamation in 1863 establishing a national observance on the last Thursday of November, and Congress fixed the holiday on the fourth Thursday in November in 1941. Washington's 1789 proclamation is therefore best understood as the first Thanksgiving day designated by the national government, not the creation of the entire tradition.