The holiday dates back to November 1621, when the newly arrived Pilgrims and the Wampanoag Indians gathered at Plymouth for an autumn harvest feast, an event regarded as America’s “first Thanksgiving.”

The Mayflower was intended to land in Virginia, but storms shifted the ship’s course north. As a result, they landed in Cape Cod, Massachusetts. After exploring the area, the Mayflower pilgrims eventually decided to stay, partially due to harsh seas and dwindling supplies. In order to establish themselves as a legitimate colony (“Plymouth,” named after the English port from which they had departed) under these dubious circumstances, 41 of the Saints and Strangers drafted and signed a document they called the Mayflower Compact. This Compact promised to create a “civil Body Politick” governed by elected officials and “just and equal laws.” It also swore allegiance to the English king. It was the first document to establish self-government in the New World and this early attempt at democracy set the stage for future colonists seeking independence from the British.

The British lost 73 dead, with another 174 wounded and 26 missing in action. The bloody encounter proved to the British that the colonists were fearsome foes who had to be taken seriously. It was the start of America’s war of independence.