Parliament declared November 6, a day of national Thanksgiving in 1879. The customs of Thanksgiving were brought to Canada by Americans who wished to remain loyal to Britain and not participate in the American Revolutionary War. The first celebration of Thanksgiving in North America occurred in 1578 in a ceremony held by Martin Frobisher and crew in Newfoundland giving thanks for surviving a difficult sea journey.
1863
Abraham Lincoln proclaimed the day a national holiday in 1863
1863 Lincoln declared Thanksgiving a holiday.
It became a national holiday in 1870 (June 26th)
Since President Abraham Lincoln made it a national holiday in 1863.
When the pilgrims celebrated their bountiful harvest, they did not realize that they were starting what was to become a yearly national holiday, but yes, we now consider their celebration the first Thanksgiving.
1941
Technically Washington did however it did not become a federal holiday with a set date until Lincoln.
Sarah Josepha Hale famously campaigned for Thanksgiving to become a holiday.
== == Christmas was declared a national holiday by Ulysses S. Grant in 1870. It's Jesus' Birthday it has to be a holiday.
Thanksgiving Day is a harvest festival. Traditionally, it is a time to give thanks for the harvest and express gratitude in general. It is primarily a North American holiday which has generally become a national secular holiday with religious origins. The date and location of the first Thanksgiving celebration is a topic of modest contention. Though the earliest attested Thanksgiving celebration was on September 8, 1565 in what is now Saint Augustine, Florida[1][2], the traditional "first Thanksgiving" is venerated as having occurred at the site of Plymouth Plantation, in 1621. Today, Thanksgiving is celebrated on the second Monday of October in Canada and on the fourth Thursday of November in the United States. Thanksgiving dinner is held on this day, usually as a gathering of family members.
1891
It was signed into law in December 1941, to be in effect from 1942.