Charles Thomson served as the secretary of the Continental Congress through its entirety (1774-1789). Through the 15 years, the Congress saw many delegates come and go. Thomson's dedication to recording the debates and decisions provided tremendous continuity.
A Philadelphia merchant and politician, Thomson had actively resisted the British for decades leading up to the American Revolutionary War.
In Vol. CI (101), 1977 of The Pennsylvania Magazine of History and Biography, Fred S. Rolater suggests that Charles Thomson was the "Prime Minister" of the United States.