There is a lot of guesswork and uncertainty in genealogy. People in the past may have put the wrong information on old records, either from genuinely not knowing, or from having something they wanted to hide. Mistakes can be made in transcriptions of documents from one location to another; even tombstones are known to sometimes have mistakes on them from the stone cutter. Census takers make mistakes in the spellings of names (and even dates and places of birth of the householders they enumerate). Those who published family genealogies back in the 19th century, when this was a popular thing to do, often relied on legend, gossip, and the erroneous family stories other people gave them.