The information that I have in the Ackerman files about this Akerman/Ackerman line seems to be somewhat different than yours but here it is:
Phinias Ackerman b 1783 Portermouth, NH, son of Peter Ackerman b 29 Feb 1748 and (1) Rachel Foss (or Locke) m. Sarah Allard, she of Farrington NH (Strafford Co). They had 4 children (but I only know of 2)
Peter b ca 1808 Farrington NH m. Betsey Scruten of Stratford, NH
Phineas W. b 1812 m. Elizabeth Chesley, dau of Daniel Chesley and wife Susan.
the father Phinias b 1783 served in the war of 1812 and in 1835 moved from Farminton to Alexandria NH(NY) Genesee; see Gazetteeer of Brafton Co., NH by Hamilton child pub 1886, part 1, page 119.
Once I finish entering this line in my genealogy program, I will post this line on the Ackerman web site