Believe I posted you on another genealogy site regarding our common line.MY GF was John M.McKee son of Benjamin Charles McKee (Twin of your Isaac) both sons of John McKee b 1810 N. Carolina who moved to Hudsonville MS ca.1833. Jon's wife was Elizabeth Lytle b 1810 in York Co SC.
The 1790 US Census for S. Carolina lists at least 23 McKees. There is a roster of families in the Colony of SC 1716-1783 that lists Adam & Daniel Mckee of the Old 96 district, ie NW corner of colony. During the Revolutionary War, patiot riders with Francis Marion 1775-1782 included five McKees: Adam,John,Joseph,Robert & Thomas who later petitioned for pensions.
My e-mail in down because of ATT problems.I have a Memphis Tel listing for M. McKee on Bayou!