William Vaughan was one of the eleven children of Samuel Vaughan, of London, and his wife Sarah Hallowell, of Boston, MA. Samuel Vaughan was a merchant who had lived in Philadelphia from in 1783-1790. William's brother Benjamin was a member of Parliament for some time, and afterward lived in America, where he was acquainted with Benjamin Franklin, publishing some of the latter's essays in 1779. Both William and Benjamin had studied at the Academy in Warrington, between Liverpool and Manchester. William pursued a life in commerce, with particular interest in the ports of England; in 1783 he was elected as a Director of the Royal Exchange Assurance Corporation. William's brother John ordered a replica of Gilbert Stuart's portrait of George Washington from the artist; the painting was a gift to his father Samuel, an admirer of Washington. After Samuel's death, the portrait passed to William. It is now in the collection of the NGA (1942.8.27).
Vaughan, William. Memoir of William Vaughan, Esq. F.R.S.. London, 1839: 5-9
Vaughan, William. Memoir of William Vaughan, Esq. F.R.S: with miscellaneous pieces relative to docks, commerce, etc.. London, 1839.