thumb|Charles ThomsonCharles Thomson (November 29, 1729 – August 16, 1824) was a Patriot leader in Philadelphia during the American Revolution and the secretary of the Continental Congress (1774–1789) throughout its existence.

Biography

Thomson was born in Gorteade townland, Maghera parish, County Londonderry, Ireland, to Scots Irish parents. After the death of his mother in 1739, his father emigrated to the British colonies in America with Charles and two or three brothers. The father died at sea, and the penniless boys were separated in America. Charles was cared for by a blacksmith in New Castle, Delaware, and was educated in New London, Pennsylvania. In 1750 he became a tutor in Latin at the Philadelphia Academy. He was a founder of the group that became the American Philosophical Society.
During the French and Indian War, Thomson was an opponent of the Pennsylvania proprietors' American Indian policies. He served as secretary at the Treaty of Easton (1758), and wrote An Enquiry into the Causes of the Alienation of the Delaware and Shawanese Indians from the British Interest (1759), which blamed the war on the proprietors. He was allied with Benjamin Franklin, the leader of the anti-proprietary party, but the two men parted politically during the Stamp Act crisis in 1765. Thomson became a leader of Philadelphia's Sons of Liberty.

Thomson was a leader in the revolutionary crisis of the early 1770s. John Adams called him the "Samuel Adams of Philadelphia". Thomson served as the secretary of the Continental Congress through its entirety. Through those 15 years, the Congress saw many delegates come and go, but Thomson's dedication to recording the debates and decisions provided continuity. Along with John Hancock, president of the Congress, Thomson's name (as secretary) appeared on the first published version of the Declaration of Independence in July 1776.
thumb|Thomson's Great Seal proposal; a modified version was accepted
Thomson role as secretary to Congress was not limited to clerical duties. According to biographer Boyd Schlenther, Thomson "took a direct role in the conduct of foreign affairs." Fred S. Rolater has suggested that Charles Thomson was essentially the "Prime Minister of the United States" (The Pennsylvania Magazine of History and Biography, vol. 101, 1977). Thomson is also noted for designing, with William Barton, the Great Seal of the United States. The Great Seal played a prominent role in the January 14, 1784 (Ratification Day) ratification of the Treaty of Paris.. Britain's representatives in Paris initially disputed the placement of the Great Seal and President Mifflin's signature, until mollified by Franklin .

But Thomson's service was not without its critics. James Searle, a close friend of John Adams, and a delegate, began a cane fight on the floor of Congress against Thomson over a claim that he was misquoted in the "Minutes" that resulted in both men being slashed in the face. Such brawls on the floor were not uncommon, and many of them were promoted by argument over Thomson's recordings. Political disagreements prevented Thomson from getting a position in the new government created by the United States Constitution. Thomson resigned as secretary of Congress in July 1789 and handed over the Great Seal, bringing an end to the Continental Congress. He spent his final years working on a translation of the Bible.

Thomson is depicted on the seven-cent postal card (and postal reply card), Scott Nos. UX68 and UY 25, issued in 1975. He was portrayed in the 1969 stage play and the 1972 film 1776 by Ralston Hill.