The forerunner to The Falls Church appears to have been founded by landowner William Gunnell, who had moved from Westmoreland County, Virginia in 1729. In the spring of 1730, he secured a minister and convened a congregation, which met in his home until 1733, when the first building was constructed. Until that time, this area was served by a clergyman who lived near present-day Quantico, and the nearest church was Pohick Church near Lorton. Like Pohick Church, the new church served Truro Parish.
George Mason was elected vestryman in 1748, as was George Washington in 1762.
By 1762 the wood building had fallen into decay and the vestry ordered a new brick building to be constructed on the same site. The next year, George Washington and George William Fairfax, as the church wardens, assumed responsibility to contract for the new building. After 1765 this church became the seat of the new Fairfax Parish. The new church was designed by Colonel James Wren, a member of the vestry.