The Plymouth Colony Pilgrims got their name long after they had all died and moved on to the next new world.
For two centuries, the relatively obscure little colonists had been simply called “Founders” or “Forefathers.”
This changed in 1854 when a publisher got his hands on the journal of William Bradford. Bradford had been governor of the Plymouth Colony during its founding years two centuries earlier.
Publishing his journal was a blockbuster event, which generated a great deal of hoopla and hype, and ultimately led to the United States adopting Thanksgiving as a national holiday.
It also inadvertently gave a new name to the colonists.
Within his journal, Bradford mentioned that the little band of religious separatists considered themselves “pilgrims” of a sort when they left Holland.
People in the 19th century, trying to find a name to differentiate these forefathers from all the other forefathers of the nation, retroactively attached the name “Pilgrims” to the colonists.