Thomas Fitzsimons, or Fitzsimmons as his last name was sometimes spelled, was born during 1741 and died on August 26, 1811. Originally from Ireland, as young man he immigrated to Philadelphia, Pennsylvania to start a career as a merchant. On November 23, 1761, he married Catharine Meade. A few months later, with his brother-in-law, he formed an extensive mercantile and commercial business which traded chiefly with the West India Islands. In 1782 Fitzsimons was elected to the congress created by the Articles of Confederation. In 1787, Fitzsimons served as a member to the Constitutional Convention, here he took an active role.
While there he argued for a strong national government, stiff restrictions on voting qualifications and office-holding, against slavery, giving Congress the power to tax imports and exports, and granting the House of Representatives and the Senate equal power in making treaties. He was elected, in 1789, to the first national House of Representatives for the state of Pennsylvania. Fitzsimons is counted among the ranks of Alexander Hamilton’s Federalists. Fitzsimons was a congress man until his defeat in 1794, after which he returned to private life.