William's 2 sons by his first wife were mentioned in his father's will in his place.
His will was dated 12/22/1789 and recorded 2/11/1790 in Hampshire. Court records of Augusta Co, VA state:
"Parsons vs McGuire -- O.S. 159; N.S. 56--Bill. May, 1808. Orator, James Parsons. William McGuire of Hampshire died testate in 1789....leaving widow, Rachel, sons, Robert and Francis, and other sons and daughters. William devised a tract which he had received from his father, Thomas McGuire. Rachel had since died. Orator bought the land from Robert and Francis. William's other children were, viz: thomas, james, nancy, Jane, Peggy, Polly, Annis. James is since dead. Robert McGuire's answer in Ross County, Ohio. Francis McGuire answers in pendleton County. His grandfather, Thomas McGuire at a very early period had put his son William in possession of the land, agreeing to make him a deed or devise. William took possession when first married and lived there until his death. Thomas survived William and died testate, will dated 19th May, 1792, and recorded in Washington County, Pennsylvania. (There was a Francis McGuire living in Brooke County, uncle to defendant Francis.) Answer by Nancy in Brooke County and Jane McGuire in Muskingum County, granddaughters of Thomas. Bond by Francis McGuire of Muskingum County, Ohio, 1809."