Benson: He is someone another Rosenbaum researcher and I came up with several years ago. I think an earlier census showed several males in the family. When Mathias moved to Carroll Co before 1830, we believed his son Benson went on to nearby Fayette Co in 1830. His name on the 1830 census does not look exactly like Rosenbaum, but close. Believe he died after the census and in 1840 his wife was still there. It does look more like Rosenbaum. I have NO other proof.
Jefferson and Melviney/Mary: They had to be the children of William. William settled in southern Dunklin Co in the Salem Township. His father John, in the Union Township in northern Dunklin Co. Jeff is living with his uncle John in 1870 in Salem Twp after Wm died. Mary b 1865 was living with a Bartholomew in 1870 in the Salem Twp and in 1880 she was recorded as Melviney G b 1865 and living with her half-brother, Milton Brown, erroneously called a cousin. These two could have not been the children of any other Rosenbaums in Dunklin Co. Again, NO absolute proof. Had this been my line, I may have gone across the River to Dunklin Co and tried to find other documentation.