OK Julie, I did some searching for our connection which is pretty distant but here's what I believe:Your Walter, age 10 months in 1910 census was the son of William H. and Alice (Northup seems right and was his second wife - first must have been Anna Paulin as he was living with her in Carthage in 1900) William and Alice lived near Charles Yerdon and both Charles and William were employed as stone masons.This leads me to think that they were brothers and the sons of Alexander D. Yerdon b. Oct 1939 (for some reason he changed his name from Albert D.) who married Fidelia and lived in Macomb in 1880 and Alexandria in 1900. Alexander D. was the son of Albert born June 3 1815 in Fort Plain NY who married Louisa Clark. Albert, in turn, was the son of Johannes born about 1775 in Fort Plain who moved his family to the North Country after 1820. Johannes and my ancestor Johan George Yerdon were most likely brothers- sons of Casper who died in 1816 at Fort Plain. I have more details and am certainly open to all corrections.The old photos I have would not go back far enough to include your side but let me know if you have any for comparison.