From what I know (published history) George Washington made a proclamtion on "thanksgiving" but like you mentioned later on Lincoln did as well and I think it was about two or three years later that congress actually adopted thanksgiving as a national holiday.
Did you by chance watch #ENJOYTHESHOW ?
RE: Dash of Sult N Papper 11/24/2022 > My message to the World on Thanksgiving Day in the U.S.A.