On January 14, 1800, the subscribers to the establishment of a Washington Society met at Gadsby's Tavern and William Maffitt was named to the committee to form the constitution and by-laws.[35] On January 28, Maffitt was appointed chaplain of the society,[36] a post which he held at least through 1803. On February 23, 1800, the society was called to meet at Gadsby's at 10 a.m. "to move in procession to the Presbyterian Meeting House where an oration will be delivered by the Rev. Mr. Maffitt, commemorative of the distinguished merits of the Illustrious Washington."[37] Again, on February 22, 1803, the Washington Society called on Maffitt to deliver a memorial sermon on the first president "at the Presbyterian Church at 12 o'clock. There will be instrumental and vocal music and the day will be announced by a discharge of 16 rounds from the Market Square."[38] On February 18, 1801, the Rev. Mr. Maffitt was elected a director of the Alexandria Library Co., and was re-elected to this post in 1802, 1803, and 1804.[39] On May 5, 1803, the Rev. Dr. Muir, pastor of the Presbyterian Meeting House, married the Rev. William Maffitt to Mrs. Harriotte Turberville.[40] Harriotte (or Henrietta) was the daughter of Richard Henry Lee, a brother of Philip Ludwell Lee, and his second wife, Anne Gaskins Pinckard, widow of Thomas Pinckard. Harriotte was born December 10, 1773 at Chantilly, the Richard Henry Lee estate in Westmoreland County.[41] Her siblings included a younger sister Sarah who married another cousin, Edmund Jennings Lee, and the youngest son, Francis Lightfoot Lee.[42] Her first marriage in December, 1794, was to Richard Lee Turberville, a cousin and neighbor, who died in 1799,[43] leaving his widow with their three children: Cornelia, Richard, and George. Richard and Harriotte Turberville had settled at Chantilly in Fairfax County and Richard apparently died there.[44] When Harriotte and William Maffitt were married, he was still principal of the Alexandria Academy, living in Alexandria, and active in community affairs. But between June 8, 1804, the date of Maffitt's resignation from the Academy, and early 1805, he moved to Chantilly with his wife, their first child, and the three children of Harriotte's first marriage. It is probable that the move took place in 1804, soon after his resignation. Legal guardian of the three Turberville children was Thomas Lee, Harriotte's oldest brother.[45] After his death in 1805, William Maffitt was named guardian.[46] In this capacity he had to keep accurate accounts of his expenditures on behalf of the children and of income received on their property, all of which were matters of court record. These records indicate that Maffitt was living at Chantilly at that time.