One thing that also is significant to me is that it proves they were married. Since I have never seen any mention of marriage records, these papers prove they were married.
And that makes a difference to 0bama’s citizenship when born out of the country. If an unmarried US citizen mother gives birth outside the country the child is a US citizen, if born to a US citizen mother married to a foreign national, the child is the nationality of the father.* So to me, even this is interesting and significant.
*(Anyone please correct me if I’m wrong!)
Good thinking....If Sr wasn’t the father thee would be no need for the BC.