Taylor Marshall at "Credo" asks the question "Is Thanksgiving Catholic?" (h/t Cato)
as evidence in support of a Catholic origin read,
...the truly “First Thanksgiving” celebration occurred on American soil on April 30, 1598 in Texas when Don Juan de Oñate declared a day of Thanksgiving to be commemorated by the Holy Sacrifice of the Mass.
But consider closely the last paragraph,
"And let everyone remember that 'Thanksgiving' in Greek is Eucharistia. Thus, the Body and Blood of Christ is the true 'Thanksgiving Meal'."
Knowing how much everyone enjoys Greek, I went to Strong's online Greek dictionary for more info,
Eucharistia, "From eucharistos; gratitude; actively, grateful language (to God, as an act of worship) -- thankfulness, (giving of) thanks(-giving)."Clicking on the link to the 5 references to eucharistia we find,
Strong's Number 2169 (εὐχαριστία: thankfulness, thanksgiving)
1 Corinthians 14:16 ἐπεὶ ἐὰν εὐλογῇς ἐν πνεύματι, ὁ ἀναπληρῶν τὸν τόπον τοῦ ἰδιώτου πῶς ἐρεῖ τὸ ἀμήν ἐπὶ τῇ σῇ εὐχαριστίᾳ; ἐπειδὴ τί λέγεις οὐκ οἶδεν·
Otherwise if you bless with the spirit, how will he who fills the place of the unlearned say the "Amen" at your giving of thanks, seeing he doesn't know what you say?
Ephesians 5:4 καὶ αἰσχρότης καὶ μωρολογία ἢ εὐτραπελία, ἃ οὐκ ἀνῆκεν ἀλλὰ μᾶλλον εὐχαριστία.
nor filthiness, nor foolish talking, nor jesting, which are not appropriate; but rather giving of thanks.
Colossians 2:7 ἐρριζωμένοι καὶ ἐποικοδομούμενοι ἐν αὐτῷ καὶ βεβαιούμενοι τῇ πίστει καθὼς ἐδιδάχθητε, περισσεύοντες (ἐν) (αὐτῇ) ἐν εὐχαριστίᾳ.
rooted and built up in him, and established in the faith, even as you were taught, abounding in it in thanksgiving.
Colossians 4:2 Τῇ προσευχῇ προσκαρτερεῖτε, γρηγοροῦντες ἐν αὐτῇ ἐν εὐχαριστίᾳ,
Continue steadfastly in prayer, watching therein with thanksgiving;
Revelation 7:12 λέγοντες, ἀμήν, ἡ εὐλογία καὶ ἡ δόξα καὶ ἡ σοφία καὶ ἡ εὐχαριστία καὶ ἡ τιμὴ καὶ ἡ δύναμις καὶ ἡ ἰσχὺς τῷ θεῷ ἡμῶν εἰς τοὺς αἰῶνας τῶν αἰώνων· ἀμήν.
saying, "Amen! Blessing, glory, wisdom, thanksgiving, honor, power, and might, be to our God forever and ever! Amen."
Giving thanks goes way back to the earliest books of the Bible. It is how we give thanks that has changed, Christians use the "eucharistia," and that is full and sufficient for the day we call "Thanksgiving." I think the answer to Taylor Marshall's question has to be a resounding "No Thank You." Perhaps the ultimate meaning and identity of Thanksgiving is Jesus at the Last Supper..."he took bread, and gave thanks to God in presence of them all: and when he had broken it, he began to eat." (Acts 27:35) "Thanksgiving" is thanks given to God, from all of us, from the beginning, and forever more.