I'd also suggest you check out the estate records on familysearch. There are several early Blount records there and you can go through them and see if any had a son named Frederick and if any correspondence happened between them and AL.
Go to www.familysearch.org
, select USA from the bottom, then select North Carolina from the list of states, then select NC Estate Files (or something similar). They are sorted by counties and then by first letter of the last name. When you get to the B's check all the old Blounts (or Keons). Chowan is also available. We've only gotten a few of the Perquimans folders completed so far.