Thanksgiving has been celebrated nationally since 1789, with the first proclamation by President George Washington after a request by Congress. The Continental Congress, the legislative body that governed the United States from 1774 to 1789, issued several "national days of prayer, humiliation, and thanksgiving", a practice that was continued by presidents Washington and Adams under the Constitution, and has manifested itself in the established American observances of Thanksgiving and the National Day of Prayer today. As President, on October 3, 1789, George Washington made the proclamation and created the first Thanksgiving Day designated by the national government of the United States of America. On the day of thanksgiving, Washington attended services at St. Paul's Chapel in New York City, and donated beer and food to imprisoned debtors in the city.
Signed, Oct 3, 1789
Sept 24, 1789- The first House of Representatives voted to recommend the First Amendment of the newly drafted Constitution to the states for ratification. The next day, Congressman Elias Boudinot from New Jersey proposed that the House and Senate jointly request of President Washington to proclaim a day of thanksgiving for "the many signal favors of Almighty God".
George Washington, declared Thursday, November 26, 1789 as a day of public thanksgiving and prayer.
Abraham Lincoln, proclaimed a national day of "Thanksgiving and Praise", for the last Thursday in November.
Franklin D. Roosevelt, moved the date to one week earlier, observed between 1939 and 1941. From 1942 onwards, Thanksgiving, by an act of Congress, signed into law by FDR, received a permanent observation date, the fourth Thursday in November, no longer at the discretion of the President