Bird
Rest in Peace
* live together for a significant period of time (not defined in any state)
Those "undefined" things are what makes the law interesting at times. I've lived through a few nights that seemed like a "significant period of time". In Texas, until 1975, it was illegal to carry a pistol (and a number of weapons) on or about your person, saddlebags, or portfolio unless you were "traveling". How far do you have to go to be "traveling"? It was interesting reading old cases and seeing how the courts' rulings changed over time.
When a common law marriage exists, the spouses receive the same legal treatment given to formally married couples, including the requirement that they go through a legal divorce to end the marriage.
Now that's the law, but the reality is that, unless there's a battle over child custody, child support, or distribution of assets, the divorce is usually a "common law" divorce, too.