My second great grandmother married my second great grandfather, Jefferson Davis, as Mrs. Mary Hubbard.
It appears back in 1846, you didn't need your maiden name on your marriage license.
Mary is a very common first name and guess what, Hubbard is a very common last name. I'm finding a lot of dead ends trying to trace down which Hubbard she was married to. She was born in Virginia and her second marriage was in Illinois. Was her first marriage Virginia? Or was it also Illinois? I don't have an exact date for her first marriage but based on the first child being born in 1837, I estimate she was married about 1835 or 36. She married her second husband, Jefferson Davis, in 1846. Both the Hubbard children were born in Illinois.
I was able to trace through census data that her daughter Julia Esther Hubbard, born in 1835, married Richard Dunham in 1861. Her last appearance on a census is 1900 and according to the Pike County ILGenweb site, she died in 1904. None of Julia's census records ask to record her father's name or mother's maiden name. (Just my luck!)
Now this could lead to my answer! If I can find Julia's death certificate, will it have her mother's maiden name?
Mary's son, John Hubbard was born about 1837. (groan...another common name). He appears in a census with the name John Hubbard Davis, then the following census as John Hubbard. I found a Civil War Draft record in 1863 for John H. Davis from Illinois and I cannot find any more data on him. Was he killed in the civil war?
In 1860 Mary Hubbard was in Illinois, her husband is missing from the census, was he serving in the Civil War? He shows up again in an 1870 census in Kansas with a couple of kids and no wife. So it looks like somewhere between 1860 and 1870 Mary Davis died. Davis is almost as common as Smith when it comes to last names and a 10 year range of Mary Davis deaths to investigate can lead to a ton of records.
I think Julia's death record may be my key! I will post an update when I find it.