I know your post was written years ago but I just happened upon it and i am very interested in your William John Sowden..
My Robert R Sowden had a brother William Sowden. My grandfather was told by his father James Sowden that his uncle " Robert Sowden's brother " went west with one of the Quintrell brothers during in the gold rush and was never heard from again.. The Quintrell I mention is the brother of Joseph Quintrell who married Annie Sowden who I believe is Roberts Sowden sister. My Robert Sowden's came from Cornwall England and settled in Allegheny Co Pennsylvania. Do you know anything about your William John Sowden parents or sibling's. Hope to hear back from you soon.