The first Thanksgiving was actually celebrated on February 21, 1621 when a band of starving pilgrims at Plymouth Rock were saved at the last minute by the arrival of a ship from Dublin bearing food from Ireland.
The Boston Post, the largest circulation newspaper in the 1920 and 1930s, discovered the earlier date for the Thanksgiving ritual. It showed that the traditional date of the autumn of 1621 was actually incorrect.
According to the "Observant Citizen," a columnist for the Boston Post, the Pilgrims in the winter of their first year were starving and faced the end of the their project to colonize the new land when “a ship arrived from overseas bearing the much needed food."
The Observant Citizen, because of anti-Irish prejudice refused to name it as an Irish ship, but it was actually The Lyon and “its provenance and that of the food was Dublin Ireland.”
It turns out, from records at the Massachusetts Historical Society, that the wife of one of the prominent Plymouth brethren was the daughter of a Dublin merchant and that it was he who chartered the vessel, loaded it with food and dispatched it to Plymouth.
The Observant Citizen, whoever he was, never admitted the Irish connection even though a number of Irish organizations challenged him on the issue.
Nonetheless the Massachusetts historical records revealed the tale giving the Irish a fair claim to saving Thanksgiving.