Maj. George Thornton (born ca. Dec. 6, 1737 [or 1743]- 1781) represented Spotsylvania County, Va. in the Convention of 1776 and the House of Delegates, 1777. He served in the Revolution under Gen. Woodford at the battle of Governor's Island, mouth of the Piankatank, in the Chesapeake Bay and afterwards was marching with his Regiment to Williamsburg when he died in April 1781. He had married in Stafford County, Va. in 1773, a first cousin, Mary Alexander (1756-1837), daughter of John Alexander. Six children were George (1774-76); John Alexander (1776); John Washington (1777); George Washington (1778-1816) who married Mary Randolph (1785-1865), daughter of Henry Randolph, of Chesterfield County, Va.; Reuben (1780-1815) who married his 3rd cousin Anna Maria Washington (1788-1816), daughter of George A. Washington, and moved to Woodville, Ms.; and Lucy Frances Thornton (1781-1846) who married her stepbrother Capt. John Posey (1774-1851). A son, John Francis Posey (1805-49), was a member of the Illinois Legislature in 1830. After Maj. George Thornton's death, Mary married Gen. Thomas Posey (1750-1818).

Maj. George Thornton's mother was Frances Gregory (c1719-ante1794), daughter of Roger (-c1730) and Mildred Washington Gregory (c1697-1747), who was born after April 1719. She married in 1736, Lt. Col. Francis Thornton IV (1711/2-49), son of Francis, Jr. (1682-) and Mary Thornton, of Spotsylvania County, Va. They lived at "The Falls," near Fredericksburg, Va. He was a large landowner, member of the House of Burgesses for Spotsylvania County, 1742-47, a justice, and served as lt. colonel of militia, 1742-49. Their six children were Francis, V (c1737-94/5); Mildred (c1739-post1804) who married in 1757, a cousin, Col. Charles Washington (1738-99), brother of Pres. George Washington; George (c1741-81); Mary (c1743-1802)(dsp) who married (1) Lt. Col. William Champe (c1739-84), and (2) in 1787, Capt. Churchill Jones (1748-1822), of Chatham, Stafford Co., Va.; Col. William (1745-1818); and Col. John Thornton (c1747-1822).

See W.G. Stanard, "The Thornton Family" (William and Mary College Quarterly, Richmond, Va., 1896-97), IV: 158-159, V: 59-60, VI: 238-239; John Augustine Washington (1920-2020), Descendants of Rev. Lawrence (c1602-52/3) and Amphyllis Twigden Washington (-1655), Five Generation Chart (Chevy Chase, Md. 1982); Dr. Justin M. Glenn, The Washingtons, A Family History, Volume One, Seven Generations of the Presidential Branch (Savas Beatie, El Dorado Hills, Ca. 2014), I: 108; James Houston Barr III, Lt. Colonel Nathaniel Pope, c1610-1660, of Virginia, Ancestor of Washington, Governors and Legislators, History of His Descendants (Louisville, Ky. 2018), 28-29.