Actually, our Allen family has supposed that William Allen's )b. 1783 in KY)father was William Allen.One vague source said he was born in 1760 and travelled to Missouri with the rest of the clan. But he did not make it to Iowa or into Whitley Allen's bible which is the source of much of the information we have.William born 1783 married Polly Burns(linked to Botetourt Co.), then Nancy McCown, and the Rachel Persinger (widow of John Persinger from Botetourt Co.) who died in Missouri.Also, have another family which must have traveled with called Allcock.
So I am working on the assumption that his father was William Allen somehow connected to Botetourt Co.
I did see somewhere that Hugh's brother(can't remember name think it was James) had a son William.
I have muddled around for 15 years with this and not found William's father.