Manor tract, moved to Kentucky in 1785, but his son, John Marshall had become a successful attorney in Richmond, as well as kept up his father's Oak Hill plantation in Fauquier County. Martin hired Marshall to secure approval of the 6th Fairfax's claim to the propriety, which he did in Fairfax v. Hite (1786). Also descendants of William Fairfax continued to assert back claims against the estates of Lord Fairfax, which had been rendered by William Fairfax prior to 1757. In order to absolve himself of these back claims, Denny Fairfax renounced his appointments of Martin and Jones, and instead appointed Bryan Fairfax, 8th Lord Fairfax of Cameron as the sole steward of the proprietary in an official transposition in London on September 21, 1784. Because Denny Fairfax was a British subject residing in England, Virginians argued he and other British relatives were "alien enemies", and thus escheat laws could confiscate his Virginia property. In 1785, the Virginia General Assembly ordered that all records, books, and documents pertaining to the proprietary's lands be confiscated by the state of Virginia and removed to the Virginia State Land Registrar's Office in Richmond. Virginia seized the remaining proprietary lands that had not yet been granted, although citizens who had already acquired grants from the proprietary could keep their land. In 1786, governor Patrick Henry began selling some of the confiscated undeveloped lands, which soon led to rounds of litigation which reached the Virginia Court of Appeals, then the U.S. Supreme Court after Martin's death, as Fairfax's Devisee v. Hunter's Lessee (1813) and Martin v. Hunter's Lessee (1816). Despite considerable litigation in Virginia, land values in the Northern Neck Proprietary continued to increase, and Thomas Marshall was only one of many who kept moving westward to the new frontier, as Martin noted in a 1790 letter: "The emigration of inhabitants is... astonishing.. Personal life, death and legacy Following the death of Lord Fairfax in 1781, Martin took his uncle's housekeeper Mrs. Crawford as his mistress, and fathered a daughter by her. Mrs. Crawford remained Martin's mistress for several years until her death. Their daughter married British captain Francis Geldart; however, she died without issue soon after their marriage, and Martin gave Geldart of Greenway Court and a number of slaves. Following the death of his daughter, Martin employed housekeeper Betsy Powers at Greenway Court. Martin died unmarried in 1798, and his will dated July