From surveyor to military officer
Preston began his public career in 1750 when he became clerk of the vestry of Augusta Parish, a post he would hold for 16 years. He would also lead troops in both the French and Indian War and American Revolutionary War, but his military career began a decade earlier as a diplomat and surveyor. In June 1752, William accompanied his uncle James Patton during negotiations to acquire land from native American tribes, and served as his secretary at the Logstown Treaty Conference. Patton soon arranged for his nephew to be apprenticed to Thomas Lewis, the surveyor the Augusta county surveyor and Patton's cousin, so in November 1752, William became a deputy surveyor. He later served as surveyor in Augusta, Botetourt, Fincastle, and Montgomery Counties, in particular surveying 36 tracts for Patton along the New River. Preston would later serve as county lieutenant for Fincastle County (much of which became Kentucky about a decade after this man's death) and Montgomery Counties (part of which later became West Virginia decades later), after the Virginia legislature further split Augusta County after the Botetourt County spinoff discussed below as its population continued to increase. In that era, the county lieutenant was the county's chief executive, appointed by the justices of the peace who were also responsible for the county administration, including overall governance of the county militia, in which all white men were required to serve.
In July 1755, Preston was commissioned captain of a ranger company, and served under his uncle James Patton until Patton was killed, then under Maj. Andrew Lewis of the Virginia Regiment. Preston survived the Draper's Meadow massacre, an attack by the Shawnee against a settlement that was part of a property later known as Smithfield Plantation, that he purchased in 1773. About a year later, Preston constructed his Smithfield Plantation home, which became his main residence.
Preston was a captain with the Virginia Regiment on the Sandy Creek Expedition in 1756. This expedition to one of the tributaries of the Clinch River failed to locate any enemies, and the insufficient food supply for the troops led to a virtual mutiny. His journal is now the only complete record of that campaign. Preston was also responsible for erecting Fort William near one of the mountain passes to protect settlers, and in early October 1756 he accompanied George Washington from Augusta Court House to the James River at Col. John Buchanan's at Luney's Ferry during Washington's survey of the frontier before taking drafted militia to relieve the company at Millar's Fort in November. In 1757 and 1758, he commanded troops at Fort Prince George in the Bullpasture area, before being qualified as major of the Augusta County militia on November 17, 1758. Despite that rank, he was captain of a ranger company stationed at Fort Young in 1759, then commissioned lieutenant colonel of the militia on August 17, 1759.
During Lord Dunmore's War of 1773–1774, while fighting against the Shawnee Indians, Preston urged Virginians to join the militia to enact revenge on the Indians and plunder their stock of horses. As the county lieutenant, one of Col. Preston's greatest contributions to the American Revolutionary War was his ability to suppress the Tories (British loyalists) from uprising in then-vast southwest Virginia during the Revolution. He also helped fight Lord Cornwallis and the British in the Carolinas.
