I recently found a copy of “The Eddy Family in America” by Ruth Story Devereux Eddy, and was happily tracing down my line, when I found this entry (p. 364)::
I knew about and have found a fair amount of information on Andrew Jackson Eddy, his wife (Francis) Louise Austin, and the three numbered sons listed. I’d never heard of Albert, Clarence, or Herbert though. This inspired me to start looking a little deeper, and I think I’ve discovered some interesting connections. Here’s what I found.
In the 1860 Census, (Andrew) Jackson Eddy; his wife (Francis) Louisa (Louise); two sons, (James) Plunkett and Arthur; and two others Byron and Isaac Austin. Given the similarity in ages and the shared last name, I think these are Francis Louisa/Louise Austin’s brothers.
There’s a record for Albert Eddy in "Michigan, Births, 1867-1902" born 20 August 1868 in Berlin, Ionia, Michigan - with father: Andrew J Eddy (born in New York) and mother: Francis L Austin (born in New York).
"Michigan, Deaths, 1867-1897" has a record of Louisa Eddy dying of consumption on 11 August 1869 in Berlin, Ionia, Michigan. It lists her parents as Daniel Austin and Sarah Austin. This is likely Francis Louise Austin, which leaves Andrew Jackson a widower and their sons motherless.
In the 1870 Census there is an Albert Eddy (age 2) living w/ Byron Austin and his wife Margaret. Byron is the right age, and his place of birth matches the Byron living w/ the Eddy’s in 1860. Andrew Jackson and three of his sons; James (Plunkett), Arthur, and Gardner are listed on the previous page of the census, just three families away.
Andrew Jackson Eddy died in 1871. (I’m still working on sources for this)
By the 1880 Census, Byron and his wife Maggie have moved to Laingsburg, Shiawassee, Michigan and no longer have Albert living with them. At this point, I can’t find any further records of Albert Eddy, which would be in line with the “died early” comment that started all this.
So, in trying to hunt down Albert Eddy I found: pretty good records of him; a likely death record for his mother, listing her parents names; and two likely uncles and an aunt - that's a pretty good haul for tracking down a missing 3rd Great Uncle.