When you hit a wall even the slightest bit of information may lead to a treasure. My great aunt said that her mother had a brother but she didn't know his name. As I was searching for her grandfather who was a Gladfelter, I found the brother's name--Orbin. Isn't that an interesting and unique name. Orbin's father died when he was still a baby, as a teen he ran away from home and was never heard of again. I went out on Ancestry.com. He was born after the 1880 census. Most of the 1890 census records were destroyed. But I found an Orbie Gladfelter on the 1900 census. He was on a farm about maybe 100 miles from where he had lived with his mother and new stepfather. However, by 1900, his family had already moved to Oregon. Several months later, I found a copy of his WWI draft registration record. I showed his name as Orb Gladfelter. It also listed his father's sister as his next of kin. This tells me that he somehow kept in touch with his father's side of the family. It gave his residence, what he looked like, where he worked. I haven't been able to find anything else. But one must have patience and drive and of course a little luck.
Orb Gladfelter is such an unusual name (at least to me) that it got me curious. His WWI draft card is online at Ancestry.com and it has more info than you indicate in your message. Also, the fact that he registered in Emporium, Cameron Co., PA but lived in Buffalo, NY, implies his birthplace because the men were required to register in their home-town if at all possible. These registrations (there were 3 based on age) were huge events. Businesses closed for the day and parades were held. Based on his age (37 in 1918), and confirmed by the draft card, he registered on Sept. 12, 1918. This doesn't mean he served, however. I would suggest searching the NY and PA census records for 1910, 1920, and 1930, if you already haven't, and try his using his middle name or initial also. He gives his name on the card as Orb Elsworth Gladfelter, and his permanent residence as 66 Main, Buffalo, NY. Hope this helps!
September, thanks for the info. Yes I actually have the copy of the WWI document. It's great that they have all that information. I know for a fact that he was born in Irving, Brown, Kansas. His older sister, my ggrandmother was born there and so was their mother. After his father died when he was 2 or 3 his mother remarried a couple of years later to a man about 25 years older than her. He already had a family, many of whom were adult age, so my gggrandmother's children were quite a bit younger than his youngest. I was thinking that maybe growing up he didn't get along with with his stepfather and when he figured he got old enough he ran away. Since the Draft has his residence in Buffalo and working in Pennsylvania, along with the census I alread have, I suspect he spent most of his life as an itinerant and possibly there aren't more census lists out there. I have not checked for his middle name though, that's an idea. I've tried checking that address but to no avail. I think as they put more records on the internet I might find something more. I don't think the WWI records have been online for more that a year.
You kind of wonder what a mother felt like to have her son run away. How much did she grieve. I think that maybe it wasn't talked about much because my great aunt didn't even know his name and he would have been her great uncle. This is the real interesting part of genealogy.
From what I've learned so far in this adventure we call genealogy, the defining points have to do with the nature of the source of the evidence . . . primary, secondary, or tertiary. Primary evidence is something being reported by someone who was there. Secondary is something being reported by someone who was informed by someone who was there, and so on. In terms of genealogical proof, primary evidence is the goal. If secondary evidence is all that is available, then more than one piece is required. In general, the best we can do is have reasonable surety of the facts, while knowing that new evidence can upset our previous conclusions at any time.
The issue that arises with individuals reporting when and where they were born, while they were technically there, they were not aware of the circumstances at the time, so it is considered secondary evidence. The birth record, which would have been reported by the parents, who were there at the time, is primary evidence. I can give an example from my own family . . . my g-grandfather reported in every document I have located that he was born at Prince Edward Island, however that is not true. He was born at Cape Breton, as were all his siblings, and the family later relocated to PEI. So, in this case, while there are several pieces of secondary evidence, they are overriden by the single piece of primary evidence.
I think you are probably right that there is no hard and fast rule about what is enough--it depends on all kinds of factors including the availability of data, the degree of precision you personally want, and, to be quite frank, the cost-benefit analysis of seeking additional or better data. Genealogists of course desire perfect precision but often have to settle for less. One way to hedge your bets when you have less than perfect documentation is to include a discussion of the source's limitations when you write your family history.
For the specific case you cite: In my opinion, speaking very generally because I don't know anything about the state of New Hampshire records, A is probably good enough for genealogy purposes. But if you need a certified copy of the birth for some reason (sometimes needed to obtain military records, for example), you would probably have to go to the town clerk's office.
This situation is the joy and pain of the geneologist. It is great joy when we find evidence and great pain when we find what we think is positve proof only to find other contradictory evidence later on. In my own experience going on 15 years of searching, I try to get at least two pieces of evidence before adding the info to my files as fact. If I later find I was wrong, I correct it and document where the conflict is. I may leave my info in with both pieces of evidence available to those who read my file, letting them then be able to follow up with their own reseach. This way between us we may get the degree of evidence we both want. I have found some truly conflicting facts from many "legal" sources (ie: census, county birth records and Bible records). The best we can hope for sometimes is to come near enough to the truth to as you say, "go on to others persons" we are researching. I have by doing so been able to later fill in the blanks left by shakey evidence.