Thomson, Charles (1729–1824), radical leader in pre-revolutionary Philadelphia, and secretary of the continental congress and of the US congress, was born 29 November 1729 in the townland of Gorteade, in the parish of Maghera, Co. Londonderry, third child among five sons and a daughter of John Thomson, a presbyterian linen bleacher, and Mary Thomson (née Houston?). In 1739 (after his wife died, possibly giving birth to Mary, who was the youngest child and only daughter) John Thomson emigrated to North America with Charles and three older sons: William, Alexander, and John. He became ill and died at sea. When the orphaned boys arrived at New Castle, Delaware, they were split up, and possibly were robbed or defrauded of whatever money they had brought with them. Some sources say that William Thomson (1727?–1796) a leader in the revolutionary war in South Carolina, was a relative, possibly an older brother. Charles lived for several years with a blacksmith's family; however, he ran away before arrangements were made for him to be apprenticed in the trade. It is said that a lady, impressed by his ability, helped him, and he made his way to New London in Chester county, Pennsylvania, to the home of schoolmaster Francis Alison (qv), from Co. Donegal, a prominent presbyterian minister and educator, who shared Thomson's Scots-Irish presbyterian background, and who can be regarded as a surrogate father for Thomson, the first of several who helped his career. Alison's school offered an excellent classical education and instilled in students an appreciation of the values associated with the Scottish enlightenment; three other former pupils, contemporaries of Thomson's, were like him signatories of the declaration of independence.
In his last years at Alison's school Thomson assisted Alison by tutoring younger boys, before he set up his own school in Delaware. In 1750 he arrived in Philadelphia to take up an appointment as a classics master in the Academy of Philadelphia, starting 7 January 1751. Francis Alison was rector of the Academy from 1752. In 1755 Thomson left the Academy for a teaching position at the Friends School in Philadelphia, where he spent five years. During Thomson's early years in Philadelphia, Benjamin Franklin became a close friend. Under Franklin's influence he joined other young Pennsylvanians, who discussed the ideas of the enlightenment in a group called the Young Junto.
Franklin and Thomson shared a belief in the importance of practical knowledge; as Thomson wrote in his ‘Plan of an American university’: ‘Learning should be connected with life and qualify its possessor for action.’ Thomson combined his business and political activities with intellectual interests. He was the catalyst for the formation of the American Society for Promoting and Propagating Useful Knowledge. It was established in Philadelphia, with corresponding members in all of the colonies, and later merged with the American Philosophical Society in 1768, with Franklin as its absentee president. The society helped establish an independent American intellectual life in the colonies, and Thomson's varied scientific and scholarly interests are evident in its archives. The society also provided an opportunity for Thomson's rapprochement with Franklin, after their friendship had cooled over politics.
He spent two years (1757–8) working for Teedyuscung, leader of the Delaware nation of Native Americans, examining the history of that people's dealings with European settlers from William Penn's treaty with them in 1722. Thomson's anonymous An enquiry into the causes of the alienation of the Delaware and Shawanese Indians from the British interest (1759) concluded that later treaties, after Penn's time, had defrauded the Delaware nation, and he criticised the policy of the current proprietors. Thomson worked on behalf of the Delaware people, acting as secretary in their dealings with officials, till the month-long meeting (October 1758) at Easton, Pennsylvania, to deal with the rival French and Native claims over the frontier at Fort Duquesne (Pittsburgh). Thompson was adopted as a member of the Delaware nation during that month. Evaluating his work with the Delawares, Thomson's biographer Boyd Stanley Schlenther suggests that it was Franklin who convinced Thomson ‘to change his views on Indian affairs to suit larger political goals’ (45). He gave up his work with the Delawares to open a dry goods shop near Franklin's home, at 324 Market St., Philadelphia, but undoubtedly the experience with the Delawares influenced his thinking about resisting the power of a political authority. In later life Thomson expressed abhorrence of slavery.
It is not easy to trace Thomson's career from the late 1750s to the 1770s because he destroyed his correspondence and papers dating from that period, but it is known that the passing of the stamp act (May 1765) prompted Thomson to make an early stand against taxation. It was not simply that the act imposed a tax on business transactions. Thomson's letter of 24 September 1765 to Franklin in London indicates that he felt that the stamp act was just the first shot fired in a wider attack on colonists’ rights. Franklin, who had hitherto failed to appreciate the strength of North American reaction to the act, advised Thomson: ‘. . . let us make as good a night of it as we can. We can still light candles.’ Thomson responded: ‘The sun of liberty is indeed fast setting, if not down already, in the American colonies’ (Franklin, xii, 207, 279, 178 n. 5). Parts of the exchange were made public when they were reprinted in the London Chronicle, 14–16 November 1765.
Thomson became a leading organiser of the Philadelphia protests against the stamp act. John Adams (1735–1826; second US president, 1797–1801) called Thomson ‘the Sam Adams of Pennsylvania’ (after Sam Adams (1722–1803), a radical Boston revolutionary). Thomson served as a delegate to the stamp act congress that met in New York in the summer of 1765. The colonists’ resistance and Franklin's advocacy of their views led to the repeal of the act in March 1766. Thomson's letter to Franklin (20 May 1766), thanking him for his work for repeal, assured Franklin that the colonists were still loyal subjects; however, as events unfolded, the repeal of the act was to lead to the first continental congress and the beginning of the united effort that would end with independence from Great Britain.
Thomson suffered financial reverses in the late 1760s. For a short time he owned a distillery business and managed an iron works outside Philadelphia, but he continued to be a political agitator who urged colonists to buy only American products and boycott British goods. Keeping in close touch with the radicals in Boston, and heedless of personal safety, he began to urge that representatives of the colonies should gather in Philadelphia to discuss their grievances. The first continental congress opened on 18 July 1774. The conservative Pennsylvanian Joseph Galloway, who would become the civilian administrator for the British when they occupied Philadelphia, blocked Thomson's selection as a delegate from Pennsylvania to the congress, but Thomson was elected its secretary. He was to serve the congress for almost fifteen years till the federal government came to power in 1789. From the beginning, Thomson kept Franklin apprised of congressional deliberations, and sent to him a copy of their petition to George III with their list of grievances. In March 1775 he told Franklin that the colonies believed that their safety lay in their union. The following month the opening shots of the American revolution were fired in Lexington, Massachusetts (19 April 1775). The second continental congress opened in September, assumed charge of the military campaign, and drew up their manifesto, the declaration of independence. On 4 July 1776 Thomson and John Hancock, president of the continental congress, were the only two signatories of the original declaration; delegates signed a later copy, but Thomson's signature does not appear on that document.
Thomson continued to serve as secretary after the revolutionary war, while the congress created a government that balanced the powers of states and a national government, first with the articles of confederation (1781), and later with the federal constitution, produced by the Philadelphia convention of 1787. His contribution in recording congressional debates and in influencing discussion and decision-making was unique in the early years of the republic. He drew no salary for the first year, but was awarded a large solid silver tea urn in recognition of his services. As well as his secretarial duties, Thomson was responsible for finalising the design of the great seal of the United States, adopted by the continental congress on 20 July 1782, and still in use. The motto of the new United States, ‘E pluribus unum’, expressed Thomson's belief in the importance of unity.
When George Washington's first government came into power in 1789, Thomson hoped to be elected senator from Pennsylvania, but he had made enemies, and was not elected to any office. He retired, somewhat resentfully, to the life of a gentleman farmer, on an estate belonging to his second wife. He corresponded with Thomas Jefferson about their shared scientific interests. He completed a history of the revolution, but – unfortunately for historians – decided against publication and destroyed his notes and manuscript. He finally returned to his early interests in the study of the classics and to his project of making the first American translation of the Old Testament from the Greek Septuagint text (1809). While the resulting translation impressed some scholars, his failure to provide a preface, as he had been advised to do, left readers without information about the original text and about his translation methods. The volume was not a financial success. A second translation project with a preface, A synopsis of the four evangelists: or, A regular history of the conception, birth, doctrine, miracles, death, resurrection and ascension of Jesus Christ in the words of the evangelists appeared in 1815. Eight years before his death, Thomson suffered the first of two strokes and spent the rest of his life in failing health and increasing senility. He died 16 August 1824 at Harriton, Lower Merion township, Montgomery county, a few miles west of Philadelphia. He was buried first at Harriton, but his body was later removed to Laurel Hill cemetery outside Philadelphia, where there is an impressive memorial.
Thomson married (1758) Ruth Mather. They had separated at some time before her death in 1770. It has been suggested that she suffered from depression after the deaths of their twin infant sons and that she may have taken her own life (Schlenther, 87). On 1 September 1774 he married Hannah, daughter of Richard Harrison and niece of the quaker politician Isaac Norris. She was a woman of some means as well as spirit, who was ‘read out’ at her quaker meeting for ‘marrying out of meeting’. She died in 1807. Neither marriage produced surviving children, and property was left to nephews.
A drawing of Thomson in profile by Pierre Eugène du Simitière is in the collection of the Historical Society of Philadelphia. There are two portraits by Charles Wilson Peale: one painted when Thomson was about 50 (c.1781) and one painted near the end of Thomson's life in 1819. Both are in the Independence National Historical Park Collection. A painting by Matthew Pratt (1794), which looks rather as if the artist painted Thomson's head above some other man's body, is in the Frick Art Reference Library. Thomson's papers are in the Library of Congress, in the Historical Societies of New York and of Pennsylvania, in the Sparks Manuscript Collection in the Houghton Library at Harvard University, and in the Princeton University Library. The papers of the continental congress, with Thomson's manuscript records, are in the National Archives, Washington DC.