Born in Rocky Mount, Edgecombe County, North Carolina in 1920 to the former Kathleen Murill and her husband, who became William F. Parkerson Sr. after naming his firstborn son after himself.

Using the GI Bill, after his wartime service, Parkerson attended the Washington and Lee University Law School, graduating in 1947.

After leaving for private legal practice, he won election as a Democrat to the Virginia House of Delegates in 1961, during the state's Massive Resistance crisis.

However, that position proved brief, as former First Lady of Virginia Eddy Dalton (a Republican) defeated his reelection bid in 1987,[2][3] She retired after one term.

He repeatedly introduced bills to create merit-based judicial selection procedure, which several times passed the senate but never the house.