The Anglican church was the established religion of the Colony of Virginia from 1619 - 1776.
The Assembly acted in 1764 and created the Fairfax Parish in the areas north of a line "by Doeg creek from the mouth thereof to Mr. George Washington's mill, and from thence, by a straight line, to the plantation, of John Munroe, and the same course continued to the line that divides the counties of Fairfax and Loudoun.
"[3] It appears that the portion of Truro that remained in that parish was disadvantaged and in 1765 the boundaries were redrawn to place Washington's plantation at Mount Vernon and nearby farms back into Truro.
Drawn over today's civil boundaries, Fairfax Parish would include all of the City of Alexandria, Arlington County, the City of Falls Church, the City of Fairfax, and the western and northern areas of Fairfax County.
They are located in present-day Arlington County, with the current house dating to 1810, after the disestablishment of the church.