I'm sorry, I can't tell you much about this William.Here's the only thing I know:
from CARROLL; the Settlements 1765-1815, page 302 (by John P. Alderman)
There were several William Allens in western Virginia in the early days, but this one is said to have been in the Revolution from North Carolina and appears to have come to Chestnut Creek a little before 1782.
He was in Montgomery Co. in 1782, taxed with three horses and two cattle. He bought a land claim from Jeremiah Clonch for a parcel of 400 acres on the waters of Chestnut and Crooked Creeks; it had been surveyed for Clonch in 1782, and the grant was made to Allen in 1785 (Grants Q-400). Later Allen had 150 acres surveyed on Little Cranberry, which Joined his other land on the east, but he sold his rights to Tavner Hays before the grant issued.
By 1787 he had prospered to the point that he owned seven horses and fifteen cattle. By 1800 he had bought 300 acres in present Grayson Co. on Meadow Creek (Grayson, D.B. 1-408; D.B. 1-409). Probably some of his family lived on the Meadow Creek farm for there were other Allens taxed at the same time: Joshua, William Jr., James, and Stephen. Joshua witnessed some of William's deeds, and the younger William was deeded some of the settler's property.
In 1795 he appraised the estate of Isaac Coulson, and in 1793 and 1794 he served as grand Juror (Grayson, W.B. 1-2; Grayson, Orders 17931794,pp.16,45).
His troubles began about 1806. The order book is missing for the earlier part of the year, but there was a big trial. The records for the October Term 1806 contain a list of witnesses who had come earlier in the year to testify against William, Joshua and Stephen Allen in some matter the subject of which is now unknown. The next year William was charged. with taking a horse, but was acquitted by the court (Grayson, Orders, 1806-1811, March Term 1807). A month later he served on the Jury in the trial of a lawsuit.
There were three suits against him in 1807 and another in 1809; some he won and some he lost. Whatever his problems were, he decided to move. He deeded his 400 acre tract to William Allen Jr. in 1805 (Grayson, D.B. 2-155). In 1807 the younger William deeded the same 400 acres to a Randolph Laurence of Hawkins Co., Tennessee; the same day the older William deeded to Laurence the Meadow Creek farm (Grayson, D.B. 2-382; D.B. 2-384).
The Grayson records do not show where he moved to, but 1807 is the last year he is taxed in the county, and the writer suspects that he followed his neighbor McCoy to Tennessee. The deeds show that William's wife was named Agnes.