Thomas Bartlett (1767-1857), a ship carpenter, was the second son of John Barlett ( -1783) of Maryland and Sarah Moore (1735-1810) of Pennsylvania. He had two siblings: Ann Bartlett (1770-1831), of Philadelphia, PA and Columbia, PA and Edward Bartlett (1766-1838), of Nova Scotia, Canada, as well as half-siblings Mary Ann Cockburn (1753-1810) and John Moore Cockburn (1755-1824) from his mother's first marriage. Thomas, Edward, and Ann were beneficiaries of their mother's will in 1810.

Thomas's father, John Bartlett, was a customs clerk at the Port of Philadelphia for the British government when the American Revolutionary War came to Philadelphia, Pennsylvania. He fled to New York City in 1778, and his property in Southwark was forfeited due to his service to the British government.

In 1807, Thomas's mother, Sarah (Moore) Bartlett, was listed as one of the heirs in the will left by her aunt, Susannah Swett. In the same year, Sarah's sister, Ann (Moore) Loudon, also left the majority of her large estate to Sarah and her daughter, Ann.

Beginning in the 1814 Philadelphia City Directory until 1822, Thomas Bartlett and his sister Ann begin to appear in the city directories together, living in Southwark, with her working as a seamstress. While living in Philadelphia, the Bartletts still owned property in Columbia, PA and in 1814-1815, Thomas Bartlett was considered a taxable freeholder of that town.