William's education consisted of home schooling. He stood about 6' tall and in his early years he assisted his father while surveying & later served as assistant surveyor for Albermarle County. During and after the French and Indian War he was appointed as an officer of the Albermarle County Militia. Margaret Jordan (1742-1812) & William married in 1756. In may 1762 Dr. Cabell, his father, gave William 1,785 acres in Amherst County. This land and an additional 460 acres became the base for the "Union Hill" plantation. Starting earlier, the General Assembly had appointed him as a commissioner for several counties to deal with the business of the king. He was also a member of the House of Burgesses for Amherst County starting in 1765 and served for subsequent terms until it was dissolved and the Revolutionary Assembly was established. He served on the Committees of Safety after 1775 & was subsequently elected the first senator to the Commonwealth of VA for the original 8th district. Additionally, by the end of 1777 he was the Presiding Justice for Amherst County, vestryman for Amherst Parish and a Trustee for Hampden-Sydney College. Later he served in the Constitutional Convention. By the time of his death he had given most of his children estates and in his will he disposed of an additional 30,000 acres.
Margaret Meredith Jordan Cabell