The census says Great-Grandpa was 9 in 1870, but the 1900 census says he was born in 1860. His tombstone says he was born 4 April 1861. The Bible record in his father's pension file has 7 April 1861. Which is correct?
First, recheck your notes and sources to be sure you didn't make a mistake. Then, analyze the information you have collected. Evaluate the sources from which you collected the information. Ask these questions and apply the answers to your problem:
- Was the information from a published source or from an original document?
- If from a published source, what do you know about its reliability?
- Who supplied the information? Was there anything to be gained or lost by giving false information?
- Was the document created at the time of the event?
- Have you misinterpreted something because you are unfamiliar with a custom, an abbreviation, or the use of certain words?
An abstract is only as good as the abstracter. Whenever possible, confirm the information by looking at the original documents.
Published sources with unsubstantiated data, and this includes the Internet, cannot be counted on to provide you with accurate information. The facts in them must always be corroborated with other sources. Even reliable published sources can have errors. There are many steps to publication, and at any point mistakes can be made, particularly in dates.
Who supplied the information? It is unwise to depend solely on the information given to the census taker. You don't know who answered the questions. Was it the head of the household? A child? A neighbor? Maybe the census taker thought he knew the answers, so he didn't bother to ask. Maybe Grandma shaved a few years off her age not wanting Grandpa to know she was older than he thought, or she didn't want her neighbor, the census taker, to know how old she really was. Human nature hasn't changed over the years; mistakes, both honest and deliberate, are made.
The accuracy of the date on the tombstone depends on the knowledge of the informant and the skill of the stone cutter. The Bible record, if made near the time of the event by someone who was an eyewitness, is probably the most accurate of the records in the preceding conflict among the dates on the tombstone, census, and Bible record.
When the family seems to have had two or more children with the same name, consider the possibility that one child died and a subsequent child was given the same name (a common custom). Or that the family was German and used the same first name for all the boys, distinguishing them by giving them a different second, or middle, name.
Perhaps you have read an abbreviation as Jas. and assumed that was James, when actually the abbreviation was Jos. for Joseph. Or you couldn't figure out why the place of birth for so many people was “do.” When you learn that “do” was an abbreviation used for “ditto,” you go back to the record and find the actual birth place that was dittoed.