John Mason (April 4, 1766 – March 19, 1849)[1][2][3][4] was an early American merchant, banker, officer (armed forces), and planter.[2] After the American Revolutionary War, Mason, his brother Thomas, and a cousin, studied with Reverend Buchnan, rector of Aquia and Pohick churches, who resided on Passapatanzy Creek.[2] As the firm expanded, it became involved in a variety of other lucrative ventures including bankinging, international commerce, the organization of foundries, and navigation and turnpike companies.His eldest brother, George Mason V, filed a will with the Fairfax County Circuit Court that their father had executed in 1773, shortly after their mother's death.He also helped President Madison and other federal officials escape into Virginia when the British burned many buildings in the new national capital during that war.[9] In 1833, financial reverses caused Mason to move his family to Clermont, four miles outside Alexandria in the Cameron Run valley.[1][2][4] The couple had ten children:[1][2][4] Following Mason's marriage to Anna Maria Murray in 1796, he settled in Georgetown on property located at the corner of present-day 25th and L Streets and Pennsylvania Avenue, Northwest.[2] After suffering a series of financial setbacks, Mason was forced to give up Analostan Island, and in 1833, the family moved to Clermont in the Cameron Run valley in Fairfax County, Virginia.