Unknown, and potentially not determinable, who this Joseph Morrow is.
Potential options:
Person:Joseph Morrow (20) - son of Ewing Morrow and Sallie Gilliam. If that were true, Joseph would have to be the oldest child of this couple by 5-10 years, and then have left no record between 1808 and 1833 when his estate is opened, including not appearing in the 1820 or 1830 local censuses.
Person:Joseph Morrow (16) - Joseph Morrow m1 Betsy Gilliam and m2 Ruth Black Brown in 1812. This is the Joseph Morrow who did leave significant records in Morgan County, and was known to be in Morgan County from the very beginning (fall of 1808, when this marriage occurred). There's no record of Betsy's death, only that she died before her mother's will in 1817. It's thus possible that she died before 1808 and Matilda was Joseph Sr.'s second wife. (This theory is potentially confirmable if descendants of Richard W. Morrow, b. 1810, so under this theory a son of Matilda, match DNA (or don't) to descendants of Sallie Gilliam, Betsy's sister--in other words, if Matilda was Richard's mother, his descendants are unrelated to descendants of Ewing m. Sallie Gilliam, whereas if Betsy is his mother, those lines are related on the Gilliam side. This line is so long ago, it will be difficult to establish this with certainty, so multiple tests likely needed.)