I have been researching King William county regarding the Newman family. I remember recently reading info about all the ferries - maybe in a gazette- it recounted the fees and routes of the ferries. There were many listed. And that might give you some names associated with the ferry. I was just exploring the Virginia Historical Society site, especially the digitized documents. There are 2 maps around the Civil War era - one of which puts names on the properties - which might be a giant help. These maps were on the VHS digitized site. Good luck!