In my father's line of the family there is a woman born in 1788 and all that has been known is her name "Elizabeth." This has led to a great deal of hair pulling over the years as one line after another attempted to connect her to this father or that husband...there have been some close fits but none you could say "takes the cake."
One of the realities a family historian has to take into consideration are those people who may have acted 'outside the social box'. In our search to identify Elizabeth, for example, we may be searching for a marriage record that did not exist. She may have never married the father of her three children; her name as known may be her maiden name; and we have to be alright with that.
There were numerous times throughout just American History when a woman might have no legal marriage record: she chose not to marry, her religious beliefs forbade or negated the need of a civil or church record, the marriage would not be recognized as legal, or marriage in her circle was seen as something done by the family or the individuals (by some patriarch of the family recognized as spiritual leader).
In many instances in remote pockets of the Carolinas, Kentucky, and Tennessee were reports who said vows, lived together as husband and wife, and then when the spring thaws came and the circuit riding preacher came back through there were weddings, often withoffspring attending.
In some instances, especially with men, they might have established a household with an African American slave or a Native American, and those unions in some times were not socially or legally recognized as valid. There can even be 'secondary' marriages or what we might call bigamy. These date back to as early as men left home to go trapping or trading elsewhere.
Politics could also play a role. Imagine for a moment a young woman whose family were dedicated patriots, committed to the cause of American independence falling in love with one of the thousands of English soldiers who served on these shores. Talk about your Romeo and Juliet!
So, sometimes, one has to think outside the box, lay aside personal issues of pride, practice tolerance and forgiveness, and recognize that the people on the family tree were not heroes and honor badges but were totally and completely human. This is important, because it allows us to learn and grow and become better people as well.