George C. Clymer was born in Philadelphia on March 16, 1739, to Deborah Fitzwater and Christopher Clymer. He was orphaned in 1740, so his wealthy maternal aunt and uncle, Hannah and William Coleman, raised him. Coleman operated a successful dry goods merchant business and provided for Clymer’s education, focusing on training him for success in business and politics. In 1765, at the age of 27, Clymer married Elizabeth Meredith, the daughter of another prominent merchant family in Philadelphia, resulting in the Society of Friends disowning her for marrying a non-Quaker. The couple had eight children together, five of whom survived to adulthood (Henry, Meredith, Margaret, Ann, and George Jr.). After Coleman’s death in 1769, Clymer received a substantial inheritance and became the head of his uncle’s shipping business, which he merged with that of the Meredith family to form a partnership with his father-in-law, Reese Meredith.

Clymer was an early supporter of independence in Pennsylvania. His mercantile success depended on low taxes and ease of trade, which led him to resent British taxation and trade restrictions (Pierpaoli 309). In fact, his income and tax liability weighed heavily on him; in 1774 Clymer had the "second highest residential tax assessment in Philadelphia and ranked third in gross income from property" (American Philosophical Society). Motivated by limiting British taxation and equipped with significant financial power, Clymer entered Pennsylvania politics in 1774 when he was elected as Alderman in Philadelphia. He co-authored and signed correspondence with the leadership of Berks County, Pennsylvania, on April 18, 1775, urgently recommending the assembly of a militia to defend against violence enacted by the British ("George Clymer to the Committee of Correspondence of the County of Berks on Preparations for War"). In 1776, he signed the Declaration of Independence as a member of the Pennsylvania Assembly. He was elected to the Continental Congress for the 1776-1777 and 1780-1782 terms and served as Treasurer of the Continental Congress with Michael Hillegas. Though Clymer rarely participated in debates in the Second Continental Congress at Independence Hall, he focused his efforts on committee work, informing the Congress on commercial and military affairs. In a particularly dramatic moment, in December 1776 Clymer refused to flee Philadelphia with the rest of the Continental Congress in the face of the approaching British army. Rather, he courageously stayed behind with George Walton and Robert Morris to maintain congressional business and ensure that supplies for the army were not interrupted. Perhaps in response to his decision or his role, the British army purposefully took an alternate route to attack Clymer's home twenty-five miles outside of the city.

Following the end of the Revolutionary War, Clymer’s political career continued to advance. He played a key role in shaping the federal government as a representative of Pennsylvania. He served as a member of the Pennsylvania legislature from 1784 to 1788. In this capacity, he fervently advocated for a bicameral legislature at the state level. Clymer was one of Pennsylvania’s representatives in the Constitutional Congress and in 1789, he signed the Constitution of the United States, making him one of only six people to sign both the Declaration of Independence and the Constitution. He was elected to the House of Representatives and served in the First Congress in 1789. Clymer’s political views aligned with the Federalist party, and he consistently advocated for consolidating war debt, establishing a national bank, and administering tariffs and excise taxes. Additionally, he shared his opinions on abolition and temperance through correspondence with Benjamin Rush, confiding his hopes that the Constitution would abolish slavery and rum, positioning excise taxes as a critical means of combating both (George Clymer to Benjamin Rush, June 18, 1789). In 1791, Clymer was appointed as the collector of national excise duties, which largely focused on taxes levied against alcoholic beverages. As a result of his unique position, Clymer played a key role in the government’s reaction to the Whiskey Rebellion in 1794, as George Washington personally appointed him to travel to Western Pennsylvania to address the unrest in the area. 

On account of his long political career and established political clout, Washington also selected Clymer to negotiate the Treaty of Colerain with the Creek and Cherokee Indians in Georgia in 1796. This treaty, as argued by Kevin Kokomoor, exemplified a uniquely Federalist approach to navigating the strained relationships between the Creek nation and Georgia frontiersmen, in which the federal representatives aligned themselves with the Creeks who sought protection from Georgians trespassing and usurping Creek land (Kokomoor 805). To do so, the treaty established the boundaries of each party’s territory, as well as a federal outpost between the two. However, in doing so, it also set a precedent for the creation of federal military or trading outposts on Creek land, and the federal treaties negotiated under Republicans following Washington supported Georgians’ continued petitions for land cessions, leading to the dispossession of the Creek Nation in Georgia (Kokomoor 842).

Clymer also provided key leadership for a series of non-political pursuits, which served to uplift Pennsylvania’s economy, academics, arts, and culture. He served as the first president of the Philadelphia Bank from 1803 until 1813. In this role, he navigated its complex relationship with the Bank of Pennsylvania, which fought to block the Philadelphia Bank’s charter entirely. He also dedicated time to social and philanthropic work; he served as the first president of the Pennsylvania Academy of the Fine Arts, the vice-president of the Philadelphia Agriculture Society, a member of the American Philosophical Society, and a trustee of the University of Pennsylvania. In 1806, he retired to Summerseat, his newly-acquired estate in Morrisville, Pennsylvania, where he lived until his death on January 23, 1813. Clymer Borough, now located in Indiana County, bears his name because he donated a significant tract of land to serve as the county seat. Clymer is remembered for his dedication to the revolutionary cause and his hand in shaping American government. His biographer, Jerry Grundfest, emphasized his pragmatism and efficacy, which made him "highly influential in making Pennsylvania a leading center of Federalism" (Grundfest 13).