I am not researching this man, just happen to have a booklet with some information on him; Mt. Jackson, VA - the Past of the Present and the Future.Some of the information on this man includes:
"Amont the earliest of the first permanent white settlers was (among others) Benjamin Allen, who acquired land near Mount Jackson and there he built a mill which was in operation prior to 1746.This is documented by an entry in Thomas Lewis' diary when he was surveying the Fairfax Line.Today the Benjamin Allen's Mill Creek has been shortened to Mill Creek."
Concerning a house and lot in town "The property can be readily traced through land deeds to 1739 when Benjamin Allen, one of three original settlers of the area, purchased a 400-acre patent."
"Reuben Moore, son of Riley Moore, had accompanied Benjamin Allen to the Valley in 1734, purchased the surveyed land."