Fredericksburg, although the Mercer family owned land west of the Appalachian mountains (some of it involved in a long-running dispute with the Hite family) and were active in the Ohio Company which encouraged trans-Appalachian settlement. When the governor dissolved the legislature, Hampshire County voters continued to elect Neville and Mercer to represent them in the first four Revolutionary Conventions, held in Williamsburg and later Richmond, although no record exists that Neville actually appeared for any but the Fourth Convention (in the winter of 1775–1776). Voters then elected Neville and established pioneer Col. Abraham Hite to represent them in the House of Delegates in 1777–1778, but Enoch Innis replaced Neville for the 1778 session. Hampshire County voters elected Neville to his final term in the House of Delegates in 1780, and he served alongside Robert Parker. During the American Revolutionary War, Neville was the Hampshire county lieutenant with the rank of colonel, and his brother (initially also a colonel) John Neville led various Virginia companies, including the 4th Virginia Regiment at the battles of Trenton and Monmouth in New Jersey, and later led the defenses of Fort Pitt (at modern day Pittsburgh, Pennsylvania). In May 1776, Joseph Neville was reimbursed 381 pounds for "necessities for Captain Abel Westfall's Company" (the 8th Virginia recruited from Hampshire county), which defended Charleston, South Carolina until February 1777. The 8th Virginia would later be consolidated with the 12th Virginia (also recruited in Hampshire County and led by Col. Abraham Hite), and withstood a siege at Charleston, South Carolina before finally surrendering in May 1780. Joseph Neville's services to the newly formed government of Virginia included disposing of the confiscated estate of John Murray, 4th Earl of Dunmore, following his ouster as the governor of Virginia. Legislators commissioned Neville and Enoch Innes (who replaced Neville in the House of Delegates) to do the job. In 1782 Neville and Colonel Alexander McLean of Pennsylvania were hired to survey the Mason–Dixon line beyond the previous survey that had demarcated the Maryland/Pennsylvania border to demarcate Pennsylvania's western boundary. They submitted a report to Governor Benjamin Harrison, and the Assembly of Virginia. Ultimately, the part of West Augusta County that Virginians called Yohogania County would become Washington County, Pennsylvania, and the remainder Ohio County and Monongelia County in Virginia (became West Virginia in the American Civil War) The legislature accepted the corrected report in 1784, and when rechecked in 1849