One has to get up close to experience just how bitter the early US atheist movement was. Some freethinkers developed their own, secular calendar to separate the counting of years from the birth of Christ. Instead, they marked the years from the execution (in 1600) of Italian philosopher Giordano Bruno by the Inquisition—an attempt to inscribe resentment, rather than celebration, into the fabric of time.
The 4As (American Association for the Advancement of Atheism) actually lobbied Congress for an official holiday called “Blamegiving Day.”
Given a choice between Thanksgiving and Blamegiving, it’s no wonder that most Americans opted for faith over atheism.