The First Thanksgiving?

In the chapter on Florida in Tony Horwitz's excellent book A Voyage Long and Strange, I read the following:
"While reading Spanish accounts of the landing at St. Augustine in 1565, he'd been struck by the mention of a thanksgiving mass, after which Menendez 'had the Indians fed and dined himself.' In other words, fifty-six years before the Pilgrim feast at Plymouth, the Spanish performed a similar ritual in St. Augustine."

So we ate at Qdoba.