I won't be celebrating Thanksgiving. :/

But in Native American History, the pilgrims were colonizers actually.

The pilgrims did encounter friendly interactions with the Natives at first, but then there was an extremely gruesome genocide which caused the rights of many indigenous people in America lose their rights, property and life due to the disagreements and greedy (horrible) mindsets of the pilgrims.
 
And considering, the rights of Indigenous people today are still at risk, hoping that not participating and indulging in recognition of Native American history, it's gratitude.