"Blaring trumpets and thundering serenaded Don Pedro Menéndez de Avilés as he waded ashore on September 8, 1565. The Spanish admiral kissed a cross held aloft by the fleet's captain, Father Francisco Lopez, then claimed Florida for both his God and his country. As curious members of the indigenous Timucua tribe looked on, the 800 newly arrived colonists gathered around a makeshift altar as Father Lopez performed a Catholic Mass of thanksgiving for their safe arrival in the newly christened settlement of St. Augustine. At the invitation of Menéndez, the Timucuans then joined the newcomers in a comunal meal.
Some Florida historians have argued that this feast - and not the one held 56 years later by th ePilgrims and the Wampanoags in Plymouth, Massachusetts - was actualy North America?s First Thankgiving. It was the first community act of religion and thanksgiving in the first permanet settlement in the land", wrote University of Florida Professor Emmeritus of History Michael Gannon in his book The Cross in the Sand."
(https://www.history.com/news/did-florida-host-the-first-thanksgiving)