There is some question as to whether Jefferson Davis had a middle initial. Jefferson did not use a middle name or initial himself, and it appears that the middle initial "F" may have arisen by tradition after his death. This tradition alleges that the "F" stands for "Finis," meaning "end" or final child. Consider that unless Samuel and Jane had agreed to end their sexual relations at that point or unless a physician had pronounced Jane unable to bear further children, they could not possibly have known at the time they named Jefferson that he was to be their last child.
However, there are other families that have children with Finis as a name, and it seems to be unrelated to their order of birth. For instance Finis Arnold Epperson in this genealogy is the first son of his father Finis Jerome Epperson, who does appear to be the last sibling in his family.
Notes on Place of birth:
A source reports Fairview as the town, and indicates it is located in Christian County, which is now Todd County. Christian County is in the south, on the border with Tennessee. It was divided at one point into Christian and Todd. County information indicates, however, that Fairview is in the north, near the Ohio border, in neither Christian nor Todd County. Fairview is apparently located in Kenton County, in the Cincinnati area.
-- ePodunk, epodunk.com
Family Tree Maker map data checker reports (requires) Fairview to be in Fleming County, in the north, but several counties east of Kenton County.