Assuming that the two acres for the courthouse were located near the head of the "gutt" and that Ballard's lot 19 was approximately the same as Buckner's 21, it is apparent that Ballard's lot must have overlapped the courthouse lots in the confusion between the two surveys. Since Mercer was living on Ballard's lot, he probably infringed on the courthouse property. Even though the courthouse had been burned and abandoned, the two acres assigned to it were required to revert to the original owner, as provided in the Act of 1667, concerning church and courthouse lands. In this case, the courthouse land, having been "deserted," had reverted to the heir of Giles Brent.
Mercer's embarrassment at this state of affairs must have been great. However, the addition by Savage of a whole new row of lots along the westerly border of the town created new acreage, sufficient both to reconcile the conflict and to provide compensatory land to satisfy the Brents. Unfortunately, the Savage survey, as we have noted, was not made official, and Mercer was forced to continue his questionable occupancy of properties whose titles were in doubt.
[Illustration: Figure 5.--KING WILLIAM COURTHOUSE, about 1725. Mercer often pleaded cases here. (From a Civil War period negative.) (_Courtesy of Historic American Buildings Survey, Library of Congress._)]
What is most significant to us in all this is the inference that the courthouse, the Ballard house which Mercer occupied, and the Structure B foundation were all in close proximity.
[60] John Mercer's Land Book, loc. cit. (footnote 12).
[61] Petition of John Mercer, loc. cit. (footnote 17).
[62] Stafford County Will Book, Liber Z, pp. 407, 431, 497.
Mercer's next purchase of Marlborough property was on July 28, 1737, when he bought the three lots granted in 1691 to George Andrews from Andrews' grandson, John Cave. Meanwhile, he began large-scale acquisitions of lands elsewhere. By 1733 he had acquired an aggregate of 8096 acres in Prince William County. In addition, he obtained a "Lease for three Lives" on three large tracts belonging to William Brent, adjoining Marlborough, so that he controlled virtually all of Potomac Neck.[63]
Thus, after 1730 we find Mercer's fortune already well established and increasing. No longer a youthful trader plying the Potomac in his sloop, he was now a gentleman planter and influential lawyer. He lived in a new house, owned some parts of Marlborough, and was building "improvements" on others. Almost overnight he had become a landed proprietor.