***I understand that in certain states, after common law spouses, who have had children together separate, there is a significant question as to wether they are still brother and sister.
Just had to slip a little Arkansas humor in, didn't you, Bob?
There is a common misconception regarding common law marriages. They actually should be terms "common law weddings." A common law marriage differs in no way from a marriage contracted under the ministrations of a priest, judge, notary public, ship captain, or any other party authorized to perform marriages. A common law marriage is NOT a second class marriage, and it definitely is not just living together. It is every bit as binding and carries the same rights and responsibilities as a ceremonial marriage. If you are married at common law, you still have to get a divorce if you wish to remarry. If you are married at common law, all the children of that union are legitimate.
My beautiful and talented soon-to-be ex-wife and I wished to be married at the Statue of Liberty. So, we wrote our vows and recited them standing before the Lady (had a German tourist snap our picture). Then we came home to Texas and did something that Texas provides; I am not sure if it is available in other states. If you are married at common law in Texas, you can file with the county clerk a "Certificate of Informal Marrige." That is your marriage certificate.
The Texas procedure eliminates the stickiest problem with common law marriages, which is proving them. In Georgia, when I practiced there, there were three elements to a marriage: The ability to contract a marriage (you're not already married, insane, too young, etc.), the present intent to be married (both of you intend from this moment on to be husband and wife, not at some time in the future), and consumation. The only difference between a ceremonial marriage and a common law marriage was that in a ceremonial marriage, consumation was presumed, so that if the groom was killed driving away from the church the newly bereaved "virgin" wife could still inherit. In a common law marriage, the husband actually had to nail the bride.
Trust me, though, there is no distinction between a common law marriage and a ceremonial marriage with respect to the responsibilities of the parties. As I lamentably am about to find out.