York County was originally named Charles River County, for Charles I, and was one of the eight shires formed in 1634. The present name was given in 1643, probably in honor of James, duke of York, the second son of Charles I.

George Mason of Gunston Hall in Fairfax County, Virginia, was born 11 December 1725. He married first Ann Eilback (1734-1773) 4 April 1750, and second Sarah Brent (1728-1794) 11 April 1780. Mason represented Fairfax County in the House of Burgesses from 1758 to 1761; in the 3rd, 4th and 5th Virginia Conventions from 1775-1776; and in the House of Delegates from 1776 to 1781 and 1786 to 1788. In the 5th Virginia Convention, Mason was appointed to the committee which wrote Virginia's first state constitution. Mason authored the Virginia Declaration of Rights, which has appeared in every subsequent state constitution. Mason attended the federal Constitutional Convention in 1787, but did not sign the document because it did not have a bill of rights at the time. This lack of a bill of rights also led to his opposition to the Constitution during the Virginia ratification convention in 1788. When the Bill of Rights was finally added to the federal Consitution, it was based on his Declaration of Rights. George Mason died at Gunston Hall, in Fairfax County, 7 October 1792.