Fort Pearsall was originally erected as a log house with a stockade by Job Pearsall (Pearsal or Pearsoll) and his brother John on their plantation in an area between Indian Mound Cemetery and the South Branch Potomac River near the river crossing of the old Fort Loudoun Road (Northwestern Turnpike) to Winchester in 1738, according to tradition. However, a look at when forts were built in the region indicates that the fort was likely built when a fort was really needed; in 1755 in the aftermath of the failed Braddock campaign in the opening days of the French and Indian War. Possibly, Job Pearsall and his brother John constructed the stockade to protect the settlers of Pearsall's Flats and the South Branch Potomac Valley. The brothers also constructed a number of homes for settlers that same year.