I've just recently tried to find my namesake ancestors again after doing this many years ago. Still finding the same roadblock. My great granndfather was Fred Louden is listed as being born in New Brunswick or Quebec. His parents are listed as Eli Louden and Thursile Dore (another record has her spelled Thursa Darea). This is where the train ends. No record of an Eli or Elijah Louden in or around Canada or New Hampshire (where Fred lived and died) can be found.
Their son Fred was born in 1873 so we can assume Eli and Thursile were born around 1850.