Irish-born Thomas FitzSimons emigrated to Philadelphia in 1760 where he first found work as a clerk in a countinghouse. He later partnered with his brother-in-law, George Meade, a prominent merchant and ship owner in Philadelphia.
At the outbreak of the American Revolution, FitzSimons raised a military company which he led into action in 1776. He also sat on Pennsylvania’s Council of Safety and on the Navy Board; his firm donated a considerable sum of money to supply the army.
In 1782 FitzSimons was elected to serve on the Continental Congress, and then went on to serve in the Pennsylvania General Assembly. In 1787 he attended the Constitutional Convention, and once it was ratified, he was elected to the House of Representatives as a Federalist. He was also a founder and director of the Bank of North America and president of the Insurance Company of North America.
In 1789 Fitzsimons was elected a trustee of the Academy and College of Philadelphia; in 1791 when the College united with the University of the State of Pennsylvania, he became a trustee of the new institution, the University of Pennsylvania.