Marcia
Assuming Catherine Mayfield Cabaniss is the mother of Alexander, Marion, and Rasmus, they would be the half brothers of Madison. This is where my family tree has hit a snag. We have not been able to identify the father of these three nor positively as Catherine's. They were all born after Peter Randolph died (No, I don't know what caused his death) and show up in Catherine's household in the 1850 Census in Tuscaloosa County. Their civil war enlistment records show they were born in Tuscaloosa County. I am assuming they are Catherine's children but have found no marriage certificate to show who she married. It is possible since she was living in Mississippi at the time of Peter's death that she could have remarried over there. I have been trying to get to Jackson or some other good Mississippi genealogical location to see if I can dig anything up over there.
I have researched John Coleman Cabaniss here at the courthouse and library until I am blue in the face but cannot connect him and Catherine. However, it does appear he was with them in the 1830s in Mississippi as I found where he had bought some land in the same area and time as Peter and Catherine did. It is possible they could have been married there. I did track John Coleman down after he left Alabama for the gold fields of California in 1849. He wound up in San Francisco running or owning an arcade (gambling hall). He died supposedly from a suicide abt 1858 and is buried in Cypress Lawn Cemetery in Colma California. In keeping with his activities back in Tuscaloosa where at one time he was part owner of a tavern among other things including a stint at farming cotton (he did own some slaves for a period as one escaped and he had put an advertisment in the paper for his return) but I am not sure he was very successful. It still may be they could have been married but it would seem strange for John Coleman to be tied up with Catherine given his background (adventurer/risk taker) since she seemed to be a regular church goer living in the country. You can find her name in the history book about Big Creek Baptist Church in Coker (now Coker Baptist) where she joined as well as in the minutes of Dunn's Creek Baptist both of which are in the library in Tuscaloosa.

Can you tell me where Madison is buried? Do you have any other info on Catherine that might give insight on who she may have married.